6th year · Dermatology

The papule is a solid and raised lesion, unlike the vesicle which contains fluid and secondary lesions such as scale or crust.

The bubble is a fluid collection that is larger than a vesicle. The pustule contains purulent fluid, the nodule is solid and the macule is flat.

Erosion is superficial, while ulceration is deeper and scarring. Lichenification and crusting are other secondary lesions.

The active annular border and the centrifugal extension suggest dermatophytia. Psoriasis is rather well limited with thick scales, eczema is often less annular and stasis dermatitis mainly affects the legs.

The dermatological approach begins with a precise semiological description before the diagnostic synthesis.

Fever, mucosal damage and skin pain are warning signals that may indicate serious drug addiction, severe infection or extensive bullous dermatosis.

A, B and C are primitive. D is a secondary lesion linked to the drying out of an exudate.

A, B and C structure the dermatological examination. D has no direct semiological value.

Describe the basic primary and secondary lesions, specify the topography, symmetry, extent, evolution, pruritus or pain, look for general and mucosal signs, then construct coherent dermatological differential diagnoses before appropriate referral.

A topical corticosteroid is designed for an identified inflammatory dermatosis, with evaluation of the site, terrain and follow-up.

Skin atrophy is one of the major local side effects of topical corticosteroids.

Local anti-inflammatory treatment can reduce the signs of a yeast infection and make diagnosis more difficult.

Local treatments can improve the skin barrier and comfort, particularly in dry and inflammatory dermatoses.

Education, compliance and monitoring are among the essential principles of dermatological therapies.

A and B may be part of an anti-inflammatory strategy. C and D refer to infections where etiological treatment must take precedence.

A, B and C are monitoring points. D is false because a recurrence requires a clinical reassessment.

Confirm the inflammatory direction, eliminate an infection or a suspicious lesion, assess the affected site, the terrain, the severity, the impact, explain the objectives, plan the monitoring of adverse effects and reassess the evolution.

Acute eczema readily combines erythema, pruritus, blisters and oozing.

Atopic dermatitis is constitutional, with xerosis and recurrent flare-ups.

Recurrence in a specific area of exposure suggests allergic contact eczema.

The well-defined, thick and scaly plaques in the areas of extension point towards psoriasis.

Active border and centrifugal extension are typical of dermatophytia of glabrous skin.

Yellowish crusts, pain and accentuated inflammation suggest impetiginization or an infectious complication.

A, B and C belong to the eczematous spectrum. D evokes a specific infectious diagnosis.

A and B are dermatological differential diagnoses; This is a possible infectious complication. D is out of dermatological scope.

Atopic dermatitis evokes an atopic terrain, xerosis, recurrent outbreaks and suggestive locations. Contact eczema is based on a relationship with specific exposure, consistent topography and recurrence upon re-exposure. Both can be pruritic, vesicular and then lichenified.

Plaque psoriasis classically manifests itself as well-defined, scaly plaques on the areas of extension.

Punctuated depressions and onycholysis can accompany psoriasis.

Inflammatory pain and stiffness should suggest psoriatic arthritis.

Psoriasis is chronic and can have a significant functional and psychosocial impact.

The annular appearance with active edge and centrifugal extension is more suggestive of dermatophytia.

The management of psoriasis depends on the severity, locations, impact and possible comorbidities.

A, B and C are classic locations. D rather suggests a scab.

A, B and C support psoriasis. D points towards dermatophytia.

Look for the extent, visible or functional locations, involvement of the scalp and nails, joint pain, pruritus or pain, psychological and social impact, triggering factors and chronicity of flare-ups.

The presence of comedones in seborrheic areas points towards acne.

Folliculitis corresponds to an infectious inflammation of the follicle, often visible by pustules centered by a hair.

Impetigo causes crusted superficial lesions, which are classically contagious.

Erysipelas is an acute febrile infection with painful inflammatory plaque.

General deterioration, significant pain and rapid extension are infectious warning signals.

The boil is a deep infection of the pilosebaceous follicle, causing a painful nodule.

A, B and C are bacterial skin infections. D is a chronic inflammatory dermatosis.

A, B and C are severity or alertness factors. D describes deep non-infectious comedonal acne.

Acne combines comedones and inflammatory lesions in seborrheic areas. Folliculitis causes pustules centered by a follicle. Impetigo is superficial, crusty, often contagious, sometimes on eczema or scratching lesions.

Dermatophytia of glabrous skin often takes on an annular appearance with an active, scaly edge.

Ringworm combines alopecia, scales and broken hair, unlike smooth alopecia areata.

Maceration of folds with active border or satellite lesions suggests mucocutaneous mycosis.

Asymmetrical friable thickening with subungual hyperkeratosis suggests onychomycosis.

An active peripheral border is a strong argument for dermatophytia.

The mycological examination as a principle helps to confirm an atypical, recurrent or difficult to diagnose mycosis.

A, B and C are classic sites. D does not correspond to the field of superficial dermatophytes.

A, B and C point to superficial mycosis. D is more compatible with psoriasis.

Dermatophytia evokes an annular lesion with an active border, centrifugal extension and sometimes contagiousness. Eczema is often very itchy, vesicular or lichenified, less well limited. Psoriasis produces well-defined, thick plaques in areas of extension, with possible involvement of the scalp and nails.

Nocturnal and collective itching is a major argument in favor of scabies.

Adherent nits and itching of the scalp suggest pediculosis.

Scratch lesions may mask specific lesions; you have to look for topography, collective context and evocative signs.

Ectoparasitoses require reflection on those around them and contagiousness.

Urticaria gives fleeting edematous papules, while scabies is supported by collective itching and suggestive topography.

A, B and C support scabies. D is more consistent with hives.

A, B and C are relevant. D is false because isolated scales have several dermatological causes.

Expected arguments: nocturnal or collective pruritus, cases in the entourage, evocative topographies, specific lesions sometimes discreet, excoriations or scratching scabs, context of promiscuity and need to evaluate close contacts.

Syphilitic chancre is classically a mildly painful indurated ulceration, often associated with lymphadenopathy.

Secondary syphilis can cause a diffuse rash with mucocutaneous involvement, particularly on the palms and soles.

Grouped, painful vesiculo-erosive lesions suggest genital herpes.

Urethritis combines urethral signs, sometimes discharge, and should lead to discussion of an STI.

STIs may be minimally symptomatic; screening, prevention and guidance are essential principles.

Management of STIs includes prevention, screening and consideration of partners in a medical setting.

A, B and C are relevant. D is false because clinical regression does not exclude an STI.

A, B, C and D can be included in the differential diagnosis of genital ulceration.

Pain, induration, number of lesions, lymphadenopathy, associated cutaneous and mucosal signs, STI context, infectious and non-infectious differential diagnoses, need for screening, prevention, medical guidance and consideration of partners must be specified.

Cutaneous leishmaniasis suggests a chronic, nodular or ulcerated lesion, in a compatible epidemiological context.

Cutaneous tuberculosis is a specific chronic infection requiring appropriate diagnostic confirmation.

A skin carcinoma can mimic or complicate the reasoning in the face of chronic ulceration.

The epidemiological context is essential to suggest leishmaniasis or a specific infection.

Chronic ulcerated lesions, particularly leishmanial lesions, can leave scars.

A, B and C support a specific infection. D evokes another dermatological framework.

A, B and C are close diagnoses. D is a non-ulcerated fleeting dermatosis.

Look for chronicity, nodular or ulcerated nature, location, geographical exposure, history, general signs, tumor, vascular and mycotic differential diagnoses, then direct towards microbiological or histological confirmation as a principle.

Urticaria manifests itself as edematous, itchy and fleeting lesions.

Angioedema with difficulty breathing or worrying mucosal damage is a sign of seriousness.

Chronicity is based on the repetition of urticarial outbreaks over time.

Pruritus without primary lesion requires a broad, dermatological and general analysis.

Prurigo involves persistent and excoriated papular lesions, whereas urticaria is fleeting.

A, B and C are characteristic. D refers to chronic scaly dermatosis.

A, B and C are dermatological causes of pruritus. D does not usually explain diffuse pruritus.

Identify possible primary lesions, distinguish secondary excoriations and causal dermatosis, look for urticaria, eczema, scabies, prurigo, drug addiction or general cause, assess the impact and identify signs of seriousness such as angioedema or mucosal damage.

The bleb is a voluminous cutaneous fluid collection.

Tense or extended bubbles, recurrent, in compatible conditions, raise the question of autoimmune bullous dermatosis.

Bullous impetigo is a superficial infection with fragile bubbles and suggestive crusts.

Purpura, mucosal damage and general deterioration are signs of seriousness in the face of a febrile rash.

A diffuse rash with mucosal damage or severe signs should raise the question of serious toxicidermy.

Extensive detachment, pain and mucosal damage may reveal serious drug or severe bullous dermatosis.

A, B and C are warning signs. D evokes a less specific and less serious situation in isolation.

A, B and C are plausible diagnoses in the face of bubbles. D does not give typical skin bubbles.

Look for the extent, skin pain, detachment, mucosal damage, purpura, necrosis, high fever, general deterioration, fragile terrain and the context of drug addiction or severe infection.

Asymmetry, irregularity, polychromy and evolution are warning signs of melanoma.

A symmetrical, homogeneous and stable nevus is less suspicious than a progressive and irregular lesion.

Basal cell carcinoma often presents as a chronic pearly lesion with telangiectasias.

A persistent keratotic or ulcerated lesion on photo-exposed skin should prompt discussion of squamous cell carcinoma.

Induration, bleeding or persistence of ulceration may reveal a skin tumor.

Exposure to ultraviolet light is a major risk factor for photo-induced skin tumors.

A progressive and irregular pigmented lesion requires specialized dermatological evaluation.

A, B and C are warning signs. D is rather reassuring.

A, B and C support a tumor suspicion. D suggests hives.

Discuss asymmetry, irregular edges, polychromy, recent development, bleeding, persistent ulceration, induration, pearly or chronic keratotic nodule, photo-exposed location, risk factors and the need for dermatological referral.

Venous ulcer is associated with chronic venous insufficiency: edema, varicose veins, stasis dermatitis and perimalleolar location.

Pain, distalization, coldness and decreased pulse point to arterial damage.

Stasis dermatitis is chronic, often bilateral, with signs of venous insufficiency.

An indurated edge, atypia or an unusual development requires discussion of a tumoral ulcer.

Varicose veins can be associated with stasis dermatitis and venous ulcers.

Management is based on the identification of the etiology and severity factors.

A, B and C support chronic venous insufficiency. D is related to urticaria.

A, B and C require broadening the reasoning. D alone is not enough to characterize an ulcer.

The venous ulcer is often perimalleolar, associated with edema, varicose veins, stasis dermatitis and ocher pigmentation. The arterial ulcer is more distal, painful, with cold skin, trophic disorders and diminished pulse. An ulcer can be mixed or atypical, requiring an etiological evaluation.

Loss of follicular openings suggests scarring alopecia.

Ringworm combines scales, broken hair and possible infectiousness; Alopecia areata is more likely to be smooth.

Asymmetry, irregular edges and recent developments are pigmentary warning signs.

A relationship between occupational exposure and eczema, particularly of the hands, supports occupational dermatosis.

Achromic depigmentation is more complete than simple post-inflammatory hypopigmentation.

A, B and C are usually non-scarring. D suggests scarring alopecia.

A, B and C support professional origin. D rather suggests an acute skin infection.

Specify whether the alopecia is scarring or not, look for scales, broken hair, inflammation, loss of follicular orifices, signs of ringworm or alopecia areata, analyze the dyschromia, its age, its evolution, the professional or inflammatory context and direct the examinations according to the hypothesis.