Dermatology

Bowen’s disease Clinical features
Bowen’s disease (BD) is the name given to an intra-epidermal carcinoma that usually presents as a slowly enlarging, erythematous, scaly plaque on the lower legs of fair-skinned older women  but other sites can also be involved. It can be confused with eczema or psoriasis, but is usually asymptomatic and does not respond to topical glucocorticoids. It may also be hard to distinguish from superficial BCC. Transformation into SCC occurs in 3% or less

Drugs- NSAIDs, retinoids, tetracyclines, furosemide

Basal cell carcinoma
The incidence of NMSC has increased dramatically in recent decades and basal cell carcinoma (BCC) accounts for more than 70% of cases. In Europe, the ratio of BCC to SCC is 4–5:1 in immunocompetent patients. It is a malignant tumour that rarely metastasises; it is thought to derive from immature pluripotent epidermal cells and is composed of cells with similarities to basal layer epidermis and appendages. Lesions typically occur at sites of moderate sun exposure, particularly the face, and are slow-growing. The incidence increases with age and males are more commonly affected. Lesions may ulcerate and invade locally; hence the term ‘rodent ulcer’.

Comedone is a characteristic lesion in acne.

Langerhans’ cells have the primary function of antigen presentation to lymphocytes.

Explanation: ‘comedone’ is a Hallmark of Acne

Prick tests are used to investigate cutaneous type I (immediate) hypersensitivity to various antigens such as pollen, house dust mite or dander.

Mild
 Hydrocortisone 0.5%, 1%, 2.5%
 Hydrocortisone 1% and fusidic acid 2% (Fucidin H)
Potent
 Betamethasone valerate 0.1% (Betnovate)  Betamethasone valerate 0.1% and clioquinol 3% (Betnovate-C)  Fluocinolone acetonide 0.025% (Synalar)  Hydrocortisone butyrate 0.1% (Locoid)  Mometasone furoate 0.1% (Elocon)

Explanation: Acne usually affects the face and often the trunk. Greasiness of the skin may be obvious (seborrhoea). The hallmark is the comedone

Soft-tissue swelling that most frequently affects the face (Fig. 4.15) but can also affect the extremities and genitalia characterizes angioedema. Involvement of the larynx or tongue may cause life-threatening respiratory tract obstruction, and oedema of the intestinal mucosa may cause abdominal pain and distension.

Reference: Davidson 23rd , Page : 1233
Explanation : Acrallentiginous or palmoplantar melanoma is more common in dark-skinned people.

Silvery scale is found in psoriasis

Explanation: Pityriasis versicolor is a persistent, superficial skin condition caused by various species of the commensal yeast Malassezia, most commonly Malassezia globosa, but sometimes M. sympadialis or M. furfur