STUDY - Technical - New Dacian's Medicine
Approaching
the Patient with Skin Conditions
Translation Draft
Here I am "starting" in presenting the elements of a new group of signs of the disease, which is particularly important from my point of view.
The difficulty of examining the skin is to distinguish the normal from the abnormal and the significant aspects from the banal ones, and to integrate the relevant signs and symptoms into an appropriate differentiated diagnosis. The fact that the skin is the most extensive organ of the body is an advantage, but also a disadvantage for the person who examines it.
It is advantageous because no special instrument is required outside of a lupe and the skin can be biopsied with reduced morbidity. However, the occasional observer may be overwhelmed by a variety of stimuli and may pass by important and subtle signs of systemic or skin disease. For example, sometimes small differences in color and shape that distinguish a malignant melanoma from a benign pigment nev can be difficult to recognize.
I will now present the most common dermatological conditions (prepare for a fairly large list): 1. vulgar acne (with frequent distribution on the face and upper dorsal region, the usual morphology being represented by closed and open comedomas, erythematous papules, pustules and sebaceous cysts), 2. rosacea (with distribution in the reddening area of the cheeks, nose, forehead and chin, the usual morphology being in the form of erythema, telangiectasis, papules and pustules); 3. seborrheic dermatitis (on the scalp and eyebrows, in the form of erythema with fatty, yellowish-brown scuba); 4. atopic dermatitis (localized in the antecubital and popliteal fossa, which can be disseminated, with the appearance of macele and erythema plaques, descuamation and lichenification, including pruritus), 5. stasis dermatitis (on the ankles and lower limbs with morphology of erythema maculare and descuamation on a hyperpigmentation of the region in association with signs of venous insufficiency), 6. dyshidrotic eczema (appearing on palms, plants, the sides of the fingers of the hands and feet, having the appearance of deep blisters), 7. allergic contact dermatitis (which occurs anywhere, the usual morphology being represented by localized erythema, blisters, scuba and pruritus - for example, fingers, earlobes for nickel, dorsal face of the foot for synthetic insoles to footwear, exposed surfaces for dermatitis given by toxicodendron, etc.), 8. psoriasis (with presence at the elbows, knees, scalp, lower dorsal, nail or generalized, with the appearance of papules and plates covered with silvery scuba and nails with punctate depressions), 9. lichen plane (present at the wrists, ankles, oral cavity, can be disseminated, morphologically with papules and violacea plates with flat roof), 10. pilar keratosis (with presence on the extension surfaces of the arms and thighs and on the buttocks, with the appearance of follicular keratotic papules with surrounding erythema), 11. melasma (present on the forehead, cheeks, temporal regions and upper lip, with the appearance of brown to brown macles), 12. vitiligo (present periorificial, trunk, extension surfaces of the extremities, flexor faces of the wrists and armpits, morphologically in the form of white-crete macele), 13. actinic keratosis (present on sun-exposed surfaces morphologically in the form of skin-colored or red-brown papules with rough, adhesive dry somas), 14. basal cell carcinoma (present on the face in the form of a pearly, telangiectasis, on sunburnt skin), 15. squamous cell carcinoma (present on the face, especially the lower lip and ears, morphologically described by endured and possibly hyperkeratotic lesions, often showing ulcerations and/ or crusts), 16. seborrheic keratosis (present on the trunk and face, the usual morphology being represented by brown plates with fatty, adherent "applied" appearance), 17. folliculitis (present in any hairy, morphologically described area of follicular pustules), 18. impetigo (present anywhere, described by papules, blisters, pustules, often with melicedic crusts), 19. herpes simplex (present on the lips or genitals, described by clustered vesicles evolving towards crusty erosions), 20. herpes zoster (present dermatomal, usually on the trunk, but can be located anywhere, described by blisters limited to a dermatoma, often painful), 21. chickenpox (present on the face, torso, relatively morphologically free extremities described by lesions that occur in groups and progress rapidly from erythematous macula to papules, then vesicles, pustules and finally crusts), 22. pitiriazis rosea (present on the trunk with the appearance of "Christmas tree", heraldic stain, followed by multiple smaller, morphological lesions described by erythematous symmetrical macles with a detached coleret or squamous), 23. tinea versicolor (present on the chest, back, abdomen and proximal on the extremities, described by hyper or hypopigmented squamous macules), 24. candidiasis (inguinal, submamar, vaginal and oral cavity, morphologically described by erythematous area macerated with satellite pustules - white brittle macles on the mucous membranes), 25. dermatophysis (present on the leg, groin, beard or scalp, described by variation with localization, for example, tinea corporis with squamous annulment macles), 25. scabies (present inguinal, armpit, interdigital to the hands and feet and submamar, described by excoriate papules, grooves and pruritus), 26. insect stings (possibly anywhere, described by erythematous papules with central points), 27. cherry angioma (present on the trunk, described by red papules containing blood), 28. cheloid (present anywhere, depending on the location of the previous lesion, described by firm tumor, pink, purple or brown), 29. dermatofibromas (present anywhere, described by the firm, reddish to brownish nodule, showing the curling of the skin at lateral pressure), 30. acrocords (present in the groin, axis and neck, described by fleshy papules), 31. urticaria (present anywhere, described by urticaria papules, sometimes with surrounding erythema and pruritus), 32. transient acantolithic dermatosis (present on the torso especially on the anterior thorax, described by erythematous papules) and (here I stop), 33. xerosis (present on the extensor faces of the extremities, especially at the feet, morphologically described by dry erythematous, descuamative and pruritus spots).
In order to help interpretations of skin lesions, different descriptive terms have been developed to characterize skin lesions. The following terms are used for the description of primary skin lesions: 1. macula (a flat, coloured lesion less than 2 cm in diameter, which is not raised above the surrounding skin - "freckles" or efelids are a prototype of the pigment macula); 2. stain (a large lesion, larger than 2 cm, flat, of different color than that of the surrounding skin - it differs from the macula only by size); 3. papula (a small, solid lesion, less than 1 cm in diameter, raised above the surrounding skin and consequently palpable - for example a dark comedon, or white dot, in acne); 4. the nodule (a larger firm lesion, between 1 and 5 cm, raised above the surrounding skin - this differs from a papule only by size - for example, the dermal nebula); 5. tumor (a round, elevated proliferation, greater than 5 cm in diameter); 6. plaque (a large lesion, greater than 1 cm, raised, with a flat ceiling in which the edges can be net - e.g. in psoriasis - or may be progressively lost in the surrounding skin - e.g. in eczematitis dermatitis); 7. vesicle (a small lesion containing liquid less than 1 cm in diameter, raised above the surface of the surrounding skin, with often visible fluid and often translucent lesions - e.g. vesicles in allergic contact dermatitis caused by Toxicodendron/ poisonous ivy); 8. pustula (a vesicle full of leukocytes - the presence of pustules does not necessarily signify the existence of an infection); 9. bubble (a prominent lesion, with liquid content, often translucent, greater than 1 cm in diameter); 10. cyst (a soft, embossed, encapsulated lesion with semisolid or liquid content); 11. urticaria/ wheat (a papule or embossed, erythematous plaque, usually representing short persistence dermal edema) and 12. telangiectasis (dilated superficial blood vessels).
Particularly useful here would be the presentation of the usual dermatological terms such as: 1. lichenification (a distinctive thickening of the skin which is characterized by a sharp drawing of the skin folds and which is thick and firm at palpation); 2. crust (dry exudate from body fluids, which may be yellow/ serous exudate or red/ hemorrhagic exudate); 3. mium (small, firm papules containing keratin and may partially resemble pustules); 4. erosion (epithelial deficiency causing a superficial solution of skin integrity); 5. ulcer (epithelial deficiency causing a deep discontinuity of the surface); 6. abrasions (linear erosions, angulars that can be covered by crusts and are caused by scratching); 7. atrophy (an acquired loss of substance; in the case of skin it may occur as a depression with intact epidermis, i.e. loss of dermal or subcutaneous tissue, or as bright, brittle, rididated, atical epidermal atrophy regions); 8. scar (a skin change secondary to trauma or inflammation; regions may be erythematous, hypopigmented or hypertrophic, depending on their age or character; localizations in hairy regions may be characterized by destruction of hair follicles).
Mastering this terminology is important not only to classify skin lesions of a particular case, but also to formulate a differential diagnosis. For example, the discovery of a large number of squamous papules, usually indicating a primary skin disease, places the patient in a diagnostic category other than the presence of hemorrhagic papules, which may indicate vasculitis or infection.
It is important to differentiate primary skin lesions from secondary skin changes. If the examiner focuses on linear erosions placed on an area of erythema and descuamation, he or she may incorrectly assume that erosion is the primary lesion and erythema and scuba are secondary, while the correct interpretation would be that the patient has a pruriginous eczema and erosions were caused by scratching.
Let's move on to the patient approach! When examining the skin it is usually advisable to examine the patient before starting anamnesis. Thus, the entire skin surface will definitely be assessed and objective signs can be integrated with the relevant information in the history. Four fundamental characteristics of any skin lesion should be noted and considered when examining the skin: 1. distribution of the rash, 2. type(s) of primary lesions, 3. the shape of the individual lesions and the arrangement of the lesions. On initial examination it is important that the patient is stripped as completely as possible.
This will minimize the risk of ignoring significant individual injuries and make it possible to fully and correctly assess the distribution of the rash. The patient should first be viewed from a distance of about 1.5 to 2 m so that the overall character of the skin and the distribution of lesions can be assessed. Indeed, the distribution of lesions often correlates closely with the diagnosis. For example, a hospitalized patient with a generalized erythematous exanthema is more likely to have a drug rash than a patient with a similar rash limited to the photoexposed portions of the face. The presence or absence of lesions on the surfaces of the mucous membranes should also be determined.
Thus, when the lesions are distributed to the elbows, knees and scalp, the most likely conditions, based solely on distribution, are psoriasis and herpetiform dermatitis. The primary lesion in psoriasis is a squamous papule that soon forms erythematous plaques covered with a white squamous, while that in herpetiform dermatitis is a urticaria papule that quickly becomes a small vesicle. In this way the identification of the primary lesion directs the examiner to the correct diagnosis. Secondary skin changes can also be quite useful.
For example, squamous represents excessive epidermis, while the crust is the result of an inadequate or inconsistent epithelial layer. Palpation of skin lesions can also provide the perception of the character of an rash. Thus, red papules on the lower extremities that fade at pressure may be the manifestation of many different diseases, but the red hemorrhagic papules that do not fade at pressure indicate the palpable purple characteristic of necrotizing vasculitis. The shape of the lesions is also an important feature. papules and flat, round erythematous plaques are common in many skin diseases. However, the lesions in the target, which are partly made up of erythematous plaques, are specific for polymorphic erythema.
Similarly, the arrangement of individual injuries is important. Erythematous and vesicle papules can occur in many conditions, but their arrangement in a specific linear order suggests an external etiology, such as allergic contact dermatitis or primary irritant dermatitis. On the contrary, lesions with a generalized arrangement are common and suggest a systemic etiology.
As in other branches of medicine, a complete history must be obtained in order to highlight the following characteristics: 1. the evolution of lesions with a. the location of the onset, the mode of spread or progression of the rash, c. duration, d. periods of improvement or remission of chronic rashes; 2. symptoms associated with rash with a. pruritus, burning, pain, paresthesia, b. which has improved the symptoms (if any), c. the period of day when the symptoms are most severe; 3. medicines received recently or in the present (prescribed as well as issued without a prescription); 4. associated systemic symptoms (e.g. malaise, fever, arthralgia); 5. associated diseases or history; 6. history of allergies; 7. the presence of photosensitivity; 8. evaluation of organ systems.
I will complete this post with some presentations related to diagnostic techniques. Many skin diseases can be diagnosed based on the overall clinical aspect, but sometimes relatively simple diagnostic procedures can provide valuable information. Most of the time they can be performed at the patient's bed with a minimum of equipment. Skin biopsy is a simple surgical procedure, however, it is important to take from the anatomical region most likely to provide diagnostic results.
This decision may require experience in skin diseases and knowledge of superficial anatomical structures in the chosen regions of the body. In this process, a small area of skin is anesthetized with 1% lidocaine with or without epinephrine. That skin lesion may be excised with a scalpel or extracted by biopsy with a preduce. In the latter technique, a preduce is pressed on the surface of the skin and rotated under pressure until it penetrates into the subcutaneous tissue. The circular biopsy is then lifted with the pen, and the base is cut with scissors. The biopsy site may not require suture closure depending on location and size.
Preparation with potassium hydroxide (KOH) is carried out for squamous skin lesions when a mycotic etiology is suspected. The edge of such a lesion is gently scraped with a scalpel blade and the resulting scoam ame is galled on a microscope blade and treated with 1-2 drops of KOH solution 10-20%. KOH dissolves keratin and allows easier visualization of fungal elements. Short heating of the blade accelerates the dissolution of keratin. When the preparation is viewed under a microscope, the light refracting hyfele will be seen more easily when the intensity of the light is reduced. This technique can be used to identify hyfele in dermatophytic infections, pseudohifele and sprouted nevs in Candida infections, fragmented hyfele and spores in tinea versicolor.
The same harvesting technique can be used to obtain scuba for the cultivation of certain pathogenic microorganisms. The Cytodiagnostic Tzank is a cytological technique most commonly used in the diagnosis of herpes infections (simplex or varicella-zosterian). A fresh blister (not a pust or a crusty lesion) is removed the ceiling and the floor of the lesion is gently scraped with a scalpel blade.
The material is then arranged on a glass blade, air-dried and colored by the Giemsa or Wright method. Multi-cleaved giant cells suggest the presence of herpes, but culture or immunofluorescence testing should be carried out to identify the virus exactly. Diascopy is used to assess whether a skin lesion fades under pressure as, for example, to determine whether a red lesion is hemorrhagic or simply contains blood.
For example, a hemangioma will fade under pressure, while a purple lesion caused by necrotizing vasculitis does not. Diascopy is used by pressing a microscope blade or magnifying glass ona particular lesion and observing the degree of discoloration that occurs. Granulomas often have an "apple jelly" appearance at diascopy. The Wood light test is performed with a Wood lamp that generates 360 nm ultraviolet radiation (or "black light") that can be used to help assess certain skin conditions.
For example, a Wood lamp will cause eritrasma (a superficial intertriginous infection caused by Corynebacterium minutissimum) to exhibit a characteristic red coral color, and the colonized lesions of Pseudomonas appear pale blue. Tinea capitis caused by certain dermatophytes such as Microsporum canis or M. Audouini exhibits yellow fluorescence. Pigmented lesions of the epidermis, such as freckles, occur accentuated, during which the dermal pigment, as it occurs in post-inflammatory hyperpigmentation, is erased under Wood light. Vitiligo appears completely white under a Wood lamp and regions until then unsuspected to be affected often become apparent.
A Wood lamp may also be useful for highlighting versicolor and recognizing macles in "maple leaf" in patients with tuberous sclerosis. Epicutaneous testing (patch tests) is used to test sensitivity to a specific antigen. In this procedure, a battery of suspected allergens is applied to the patient's back under occlusive dressing and is allowed skin contact for 48 hours. The dressings are then removed and the surface is examined for delayed hypersensitivity reactions (e.g. erythema, edema or papulovesicles). This test is optimally performed by physicians with special qualifications in epicutan testing and is often useful in assessing patients with chronic dermatitis.
That's enough for today! I'll continue with common skin conditions.
Here I am "starting" in presenting the elements of a new group of signs of the disease, which is particularly important from my point of view.
The difficulty of examining the skin is to distinguish the normal from the abnormal and the significant aspects from the banal ones, and to integrate the relevant signs and symptoms into an appropriate differentiated diagnosis. The fact that the skin is the most extensive organ of the body is an advantage, but also a disadvantage for the person who examines it.
It is advantageous because no special instrument is required outside of a lupe and the skin can be biopsied with reduced morbidity. However, the occasional observer may be overwhelmed by a variety of stimuli and may pass by important and subtle signs of systemic or skin disease. For example, sometimes small differences in color and shape that distinguish a malignant melanoma from a benign pigment nev can be difficult to recognize.
I will now present the most common dermatological conditions (prepare for a fairly large list): 1. vulgar acne (with frequent distribution on the face and upper dorsal region, the usual morphology being represented by closed and open comedomas, erythematous papules, pustules and sebaceous cysts), 2. rosacea (with distribution in the reddening area of the cheeks, nose, forehead and chin, the usual morphology being in the form of erythema, telangiectasis, papules and pustules); 3. seborrheic dermatitis (on the scalp and eyebrows, in the form of erythema with fatty, yellowish-brown scuba); 4. atopic dermatitis (localized in the antecubital and popliteal fossa, which can be disseminated, with the appearance of macele and erythema plaques, descuamation and lichenification, including pruritus), 5. stasis dermatitis (on the ankles and lower limbs with morphology of erythema maculare and descuamation on a hyperpigmentation of the region in association with signs of venous insufficiency), 6. dyshidrotic eczema (appearing on palms, plants, the sides of the fingers of the hands and feet, having the appearance of deep blisters), 7. allergic contact dermatitis (which occurs anywhere, the usual morphology being represented by localized erythema, blisters, scuba and pruritus - for example, fingers, earlobes for nickel, dorsal face of the foot for synthetic insoles to footwear, exposed surfaces for dermatitis given by toxicodendron, etc.), 8. psoriasis (with presence at the elbows, knees, scalp, lower dorsal, nail or generalized, with the appearance of papules and plates covered with silvery scuba and nails with punctate depressions), 9. lichen plane (present at the wrists, ankles, oral cavity, can be disseminated, morphologically with papules and violacea plates with flat roof), 10. pilar keratosis (with presence on the extension surfaces of the arms and thighs and on the buttocks, with the appearance of follicular keratotic papules with surrounding erythema), 11. melasma (present on the forehead, cheeks, temporal regions and upper lip, with the appearance of brown to brown macles), 12. vitiligo (present periorificial, trunk, extension surfaces of the extremities, flexor faces of the wrists and armpits, morphologically in the form of white-crete macele), 13. actinic keratosis (present on sun-exposed surfaces morphologically in the form of skin-colored or red-brown papules with rough, adhesive dry somas), 14. basal cell carcinoma (present on the face in the form of a pearly, telangiectasis, on sunburnt skin), 15. squamous cell carcinoma (present on the face, especially the lower lip and ears, morphologically described by endured and possibly hyperkeratotic lesions, often showing ulcerations and/ or crusts), 16. seborrheic keratosis (present on the trunk and face, the usual morphology being represented by brown plates with fatty, adherent "applied" appearance), 17. folliculitis (present in any hairy, morphologically described area of follicular pustules), 18. impetigo (present anywhere, described by papules, blisters, pustules, often with melicedic crusts), 19. herpes simplex (present on the lips or genitals, described by clustered vesicles evolving towards crusty erosions), 20. herpes zoster (present dermatomal, usually on the trunk, but can be located anywhere, described by blisters limited to a dermatoma, often painful), 21. chickenpox (present on the face, torso, relatively morphologically free extremities described by lesions that occur in groups and progress rapidly from erythematous macula to papules, then vesicles, pustules and finally crusts), 22. pitiriazis rosea (present on the trunk with the appearance of "Christmas tree", heraldic stain, followed by multiple smaller, morphological lesions described by erythematous symmetrical macles with a detached coleret or squamous), 23. tinea versicolor (present on the chest, back, abdomen and proximal on the extremities, described by hyper or hypopigmented squamous macules), 24. candidiasis (inguinal, submamar, vaginal and oral cavity, morphologically described by erythematous area macerated with satellite pustules - white brittle macles on the mucous membranes), 25. dermatophysis (present on the leg, groin, beard or scalp, described by variation with localization, for example, tinea corporis with squamous annulment macles), 25. scabies (present inguinal, armpit, interdigital to the hands and feet and submamar, described by excoriate papules, grooves and pruritus), 26. insect stings (possibly anywhere, described by erythematous papules with central points), 27. cherry angioma (present on the trunk, described by red papules containing blood), 28. cheloid (present anywhere, depending on the location of the previous lesion, described by firm tumor, pink, purple or brown), 29. dermatofibromas (present anywhere, described by the firm, reddish to brownish nodule, showing the curling of the skin at lateral pressure), 30. acrocords (present in the groin, axis and neck, described by fleshy papules), 31. urticaria (present anywhere, described by urticaria papules, sometimes with surrounding erythema and pruritus), 32. transient acantolithic dermatosis (present on the torso especially on the anterior thorax, described by erythematous papules) and (here I stop), 33. xerosis (present on the extensor faces of the extremities, especially at the feet, morphologically described by dry erythematous, descuamative and pruritus spots).
In order to help interpretations of skin lesions, different descriptive terms have been developed to characterize skin lesions. The following terms are used for the description of primary skin lesions: 1. macula (a flat, coloured lesion less than 2 cm in diameter, which is not raised above the surrounding skin - "freckles" or efelids are a prototype of the pigment macula); 2. stain (a large lesion, larger than 2 cm, flat, of different color than that of the surrounding skin - it differs from the macula only by size); 3. papula (a small, solid lesion, less than 1 cm in diameter, raised above the surrounding skin and consequently palpable - for example a dark comedon, or white dot, in acne); 4. the nodule (a larger firm lesion, between 1 and 5 cm, raised above the surrounding skin - this differs from a papule only by size - for example, the dermal nebula); 5. tumor (a round, elevated proliferation, greater than 5 cm in diameter); 6. plaque (a large lesion, greater than 1 cm, raised, with a flat ceiling in which the edges can be net - e.g. in psoriasis - or may be progressively lost in the surrounding skin - e.g. in eczematitis dermatitis); 7. vesicle (a small lesion containing liquid less than 1 cm in diameter, raised above the surface of the surrounding skin, with often visible fluid and often translucent lesions - e.g. vesicles in allergic contact dermatitis caused by Toxicodendron/ poisonous ivy); 8. pustula (a vesicle full of leukocytes - the presence of pustules does not necessarily signify the existence of an infection); 9. bubble (a prominent lesion, with liquid content, often translucent, greater than 1 cm in diameter); 10. cyst (a soft, embossed, encapsulated lesion with semisolid or liquid content); 11. urticaria/ wheat (a papule or embossed, erythematous plaque, usually representing short persistence dermal edema) and 12. telangiectasis (dilated superficial blood vessels).
Particularly useful here would be the presentation of the usual dermatological terms such as: 1. lichenification (a distinctive thickening of the skin which is characterized by a sharp drawing of the skin folds and which is thick and firm at palpation); 2. crust (dry exudate from body fluids, which may be yellow/ serous exudate or red/ hemorrhagic exudate); 3. mium (small, firm papules containing keratin and may partially resemble pustules); 4. erosion (epithelial deficiency causing a superficial solution of skin integrity); 5. ulcer (epithelial deficiency causing a deep discontinuity of the surface); 6. abrasions (linear erosions, angulars that can be covered by crusts and are caused by scratching); 7. atrophy (an acquired loss of substance; in the case of skin it may occur as a depression with intact epidermis, i.e. loss of dermal or subcutaneous tissue, or as bright, brittle, rididated, atical epidermal atrophy regions); 8. scar (a skin change secondary to trauma or inflammation; regions may be erythematous, hypopigmented or hypertrophic, depending on their age or character; localizations in hairy regions may be characterized by destruction of hair follicles).
Mastering this terminology is important not only to classify skin lesions of a particular case, but also to formulate a differential diagnosis. For example, the discovery of a large number of squamous papules, usually indicating a primary skin disease, places the patient in a diagnostic category other than the presence of hemorrhagic papules, which may indicate vasculitis or infection.
It is important to differentiate primary skin lesions from secondary skin changes. If the examiner focuses on linear erosions placed on an area of erythema and descuamation, he or she may incorrectly assume that erosion is the primary lesion and erythema and scuba are secondary, while the correct interpretation would be that the patient has a pruriginous eczema and erosions were caused by scratching.
Let's move on to the patient approach! When examining the skin it is usually advisable to examine the patient before starting anamnesis. Thus, the entire skin surface will definitely be assessed and objective signs can be integrated with the relevant information in the history. Four fundamental characteristics of any skin lesion should be noted and considered when examining the skin: 1. distribution of the rash, 2. type(s) of primary lesions, 3. the shape of the individual lesions and the arrangement of the lesions. On initial examination it is important that the patient is stripped as completely as possible.
This will minimize the risk of ignoring significant individual injuries and make it possible to fully and correctly assess the distribution of the rash. The patient should first be viewed from a distance of about 1.5 to 2 m so that the overall character of the skin and the distribution of lesions can be assessed. Indeed, the distribution of lesions often correlates closely with the diagnosis. For example, a hospitalized patient with a generalized erythematous exanthema is more likely to have a drug rash than a patient with a similar rash limited to the photoexposed portions of the face. The presence or absence of lesions on the surfaces of the mucous membranes should also be determined.
Thus, when the lesions are distributed to the elbows, knees and scalp, the most likely conditions, based solely on distribution, are psoriasis and herpetiform dermatitis. The primary lesion in psoriasis is a squamous papule that soon forms erythematous plaques covered with a white squamous, while that in herpetiform dermatitis is a urticaria papule that quickly becomes a small vesicle. In this way the identification of the primary lesion directs the examiner to the correct diagnosis. Secondary skin changes can also be quite useful.
For example, squamous represents excessive epidermis, while the crust is the result of an inadequate or inconsistent epithelial layer. Palpation of skin lesions can also provide the perception of the character of an rash. Thus, red papules on the lower extremities that fade at pressure may be the manifestation of many different diseases, but the red hemorrhagic papules that do not fade at pressure indicate the palpable purple characteristic of necrotizing vasculitis. The shape of the lesions is also an important feature. papules and flat, round erythematous plaques are common in many skin diseases. However, the lesions in the target, which are partly made up of erythematous plaques, are specific for polymorphic erythema.
Similarly, the arrangement of individual injuries is important. Erythematous and vesicle papules can occur in many conditions, but their arrangement in a specific linear order suggests an external etiology, such as allergic contact dermatitis or primary irritant dermatitis. On the contrary, lesions with a generalized arrangement are common and suggest a systemic etiology.
As in other branches of medicine, a complete history must be obtained in order to highlight the following characteristics: 1. the evolution of lesions with a. the location of the onset, the mode of spread or progression of the rash, c. duration, d. periods of improvement or remission of chronic rashes; 2. symptoms associated with rash with a. pruritus, burning, pain, paresthesia, b. which has improved the symptoms (if any), c. the period of day when the symptoms are most severe; 3. medicines received recently or in the present (prescribed as well as issued without a prescription); 4. associated systemic symptoms (e.g. malaise, fever, arthralgia); 5. associated diseases or history; 6. history of allergies; 7. the presence of photosensitivity; 8. evaluation of organ systems.
I will complete this post with some presentations related to diagnostic techniques. Many skin diseases can be diagnosed based on the overall clinical aspect, but sometimes relatively simple diagnostic procedures can provide valuable information. Most of the time they can be performed at the patient's bed with a minimum of equipment. Skin biopsy is a simple surgical procedure, however, it is important to take from the anatomical region most likely to provide diagnostic results.
This decision may require experience in skin diseases and knowledge of superficial anatomical structures in the chosen regions of the body. In this process, a small area of skin is anesthetized with 1% lidocaine with or without epinephrine. That skin lesion may be excised with a scalpel or extracted by biopsy with a preduce. In the latter technique, a preduce is pressed on the surface of the skin and rotated under pressure until it penetrates into the subcutaneous tissue. The circular biopsy is then lifted with the pen, and the base is cut with scissors. The biopsy site may not require suture closure depending on location and size.
Preparation with potassium hydroxide (KOH) is carried out for squamous skin lesions when a mycotic etiology is suspected. The edge of such a lesion is gently scraped with a scalpel blade and the resulting scoam ame is galled on a microscope blade and treated with 1-2 drops of KOH solution 10-20%. KOH dissolves keratin and allows easier visualization of fungal elements. Short heating of the blade accelerates the dissolution of keratin. When the preparation is viewed under a microscope, the light refracting hyfele will be seen more easily when the intensity of the light is reduced. This technique can be used to identify hyfele in dermatophytic infections, pseudohifele and sprouted nevs in Candida infections, fragmented hyfele and spores in tinea versicolor.
The same harvesting technique can be used to obtain scuba for the cultivation of certain pathogenic microorganisms. The Cytodiagnostic Tzank is a cytological technique most commonly used in the diagnosis of herpes infections (simplex or varicella-zosterian). A fresh blister (not a pust or a crusty lesion) is removed the ceiling and the floor of the lesion is gently scraped with a scalpel blade.
The material is then arranged on a glass blade, air-dried and colored by the Giemsa or Wright method. Multi-cleaved giant cells suggest the presence of herpes, but culture or immunofluorescence testing should be carried out to identify the virus exactly. Diascopy is used to assess whether a skin lesion fades under pressure as, for example, to determine whether a red lesion is hemorrhagic or simply contains blood.
For example, a hemangioma will fade under pressure, while a purple lesion caused by necrotizing vasculitis does not. Diascopy is used by pressing a microscope blade or magnifying glass ona particular lesion and observing the degree of discoloration that occurs. Granulomas often have an "apple jelly" appearance at diascopy. The Wood light test is performed with a Wood lamp that generates 360 nm ultraviolet radiation (or "black light") that can be used to help assess certain skin conditions.
For example, a Wood lamp will cause eritrasma (a superficial intertriginous infection caused by Corynebacterium minutissimum) to exhibit a characteristic red coral color, and the colonized lesions of Pseudomonas appear pale blue. Tinea capitis caused by certain dermatophytes such as Microsporum canis or M. Audouini exhibits yellow fluorescence. Pigmented lesions of the epidermis, such as freckles, occur accentuated, during which the dermal pigment, as it occurs in post-inflammatory hyperpigmentation, is erased under Wood light. Vitiligo appears completely white under a Wood lamp and regions until then unsuspected to be affected often become apparent.
A Wood lamp may also be useful for highlighting versicolor and recognizing macles in "maple leaf" in patients with tuberous sclerosis. Epicutaneous testing (patch tests) is used to test sensitivity to a specific antigen. In this procedure, a battery of suspected allergens is applied to the patient's back under occlusive dressing and is allowed skin contact for 48 hours. The dressings are then removed and the surface is examined for delayed hypersensitivity reactions (e.g. erythema, edema or papulovesicles). This test is optimally performed by physicians with special qualifications in epicutan testing and is often useful in assessing patients with chronic dermatitis.
That's enough for today! I'll continue with common skin conditions.
A weekend of the best!
Dorin, Merticaru