WBR0600
| Author | [[PageAuthor::Ayokunle Olubaniyi, M.B,B.S [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pathology |
| Sub Category | SubCategory::Dermatology |
| Prompt | [[Prompt::A 47-year old man presented to the dermatology clinic with a 4-year history of a pruritic lesion shown below; it initially started as a small dimple after been stung by a bee, and gradually became raised, thickened, and darkened following repeated scratching over the years.
Which of the following is the most appropriate diagnosis?]] |
| Answer A | AnswerA::Lichen sclerosus |
| Answer A Explanation | [[AnswerAExp::Lichen sclerosus is a skin disorder that mainly affects the vulva in women and the penis in men. The skin appears thin, whitish, and wrinkled. It appears to be commoner among post-menopausal women, although men, children, and premenopausal women may be affected. Common sites include: near the clitoris, labia, and in the anal region. Other skin surfaces affected include: thighs, breasts, wrists, shoulders, neck, and even the inside the mouth. Symptoms include itch, soreness, dyspareunia, and changes in the appearance of affected skin. The exact etiology is still unknown, although it has been postulated to have genetic, autoimmune and infectious origin. Diagnosis is by biopsy.]] |
| Answer B | AnswerB::Lichen simplex chronicus |
| Answer B Explanation | AnswerBExp::Lichen simplex chronicus (LSC) refers to thickening of the skin secondary to repetitive scratching or rubbing which makes the skin thick, leathery, and brownish. Treatment is with topical steroids. |
| Answer C | AnswerC::Lichen planus |
| Answer C Explanation | [[AnswerCExp::Lichen planus is a chronic inflammatory disease that affects the skin and the mucous membrane. It commonly affects the middle aged groups. It may affect the skin, oral cavity, genitalia, scalp, nails, or esophagus. The clinical features of cutaneous lichen planus are described as the four P’s – pruritic, purple, polygonal papules or plaques. Diagnosis is by biopsy. Topical corticosteroids are the first line in treatment.]] |
| Answer D | AnswerD::Allergic contact dermatitis |
| Answer D Explanation | [[AnswerDExp::Contact dermatitis is an inflammation of the skin induced by chemicals that directly damage the skin (irritant contant contact dermatitis) and by specific sensitivity in the case of allergic contact dermatitis, for example, bee sting, nickel, rubber gloves, e.t.c Clinical presentation, which is usually preceded by the exposure to the allergen, involves the appearance of pruritic papules and vesicles on an erythematous base, and may become either hyper- or hypo-pigmented with time. Topical corticosteroids are the mainstay of treatment. Other therapies include the use of oral antihistamines for symptomatic relief of pruritus, tacrolimus, which is an immune modulator.]] |
| Answer E | AnswerE::Vitiligo |
| Answer E Explanation | AnswerEExp::This is an autoimmune disorder against the melanocyte cells in the skin. It manifests as loss of pigment, resulting in irregular pale patches of skin. Treatment is with corticosteroid cream and phototherapy using PUVA. |
| Right Answer | RightAnswer::B |
| Explanation | [[Explanation::Lichen simplex chronicus (LSC) refers to thickening of the skin secondary to repetitive scratching or rubbing which makes the skin thick, leathery, and brownish. Common areas affected include: scalp, nape of neck, extensor forearms and elbows, vulva and scrotum, upper medial thighs, knees, lower legs, and ankles. Treatment is with topical steroids. Educational Objective: |
| Approved | Approved::No |
| Keyword | WBRKeyword::Lichen simplex chronicus |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
