Dermatology

New guidelines recommend benzoyl peroxide for most patients with comedonal acne and all patients with inflammatory acne-especially those who receive a topical or oral antibiotic as therapy, in whom it can prevent antibiotic resistance.

Would Mohs surgery be indicated for this 68-year-old man?

Texting without gloves while sitting on a ski lift explains the onset of this rash in a patient with a long history of widespread psoriasis.

This woman was snowboarding over a very cold weekend and developed a pustular rash at night after her activities.

These discolored, scaly lesions on this young man’s trunk have recurred for the past 2 summers. He reports that the rash becomes “irritated and itchy” when he is in the sun.

A macular rash has been spreading for 5 days after the cheerful child started amoxicillin therapy. What’s the most likely cause?

This rash began as a small red patch about 10 days earlier while the patient was at wrestling camp.

Does this rash look like impetigo? Herpes? Tinea? Cellulitis? Here's a close look and a link to the answer and discussion.

Drugs, diseases, guidelines, databases-all at the touch of an app. Here: a selection of smartphone/tablet applications that may make your clinical practice a little easier this coming year.

Dermatofibromas may present as papules or nodules that are elevated or slightly depressed. Suspected etiology includes skin injury such as insect bites.

This relatively uncommon inflammatory dermal process has previously been associated with diabetes mellitus and more recently with hyperlipidemia.

Nail clubbing may occur with many conditions. In these two patients, it heralded lung cancer.

A 23-year-old African American woman had variably shaped areas of atrophy and hypopigmentation on the face and ear. Your diagnosis?

Allergic contact dermatitis is common, can be debilitating for patients, and may mimic other dermatoses.

Fewer than two-thirds of men know the signs of skin cancer and the younger they are the less likely they are to believe they are at risk for the disease, according to a national survey.

Tinea versicolor presents with hyperpigmented and hypopigmented coalescing thin scaly plaques and macules.Typically they appear on the trunk and the upper back. It is more common in warm humid climates.

The rash has been present for 2 years. Originally on the trunk and extremities it has now spread to her face and hands. She has been diagnosed as having and been unsuccessfully treated for nummular eczema and tinea corporis. What's your Dx?

Lichen spinulosus is a rare, hyperkeratotic dermatosis similar to keratosis pilaris. It is most common in children, adolescents, young adults with male predominance. Treatment includes keratolytics and emollients.

The asymptomatic atrophic brown plaques on this woman’s legs were diagnosed as necrobiosis lipoidica. The differential diagnosis included lupus erythematosus and granuloma annulare.

Polymorphic light eruption, phototoxicity, solar purpura, basal cell carcinoma, squamous cell carcinoma, keratoacanthoma, venous lakes, photosensitivity-a look at the many adverse effects of too much sun exposure.

Recent travel to the Caribbean is the key clue that led to the diagnosis of dengue fever, which caused maculopapular rash, fever, headaches, and body aches.

Small and nondescript, subungual splinter hemorrhages should prompt further investigation.

Thin dark lines beneath the fingernails are the only physical findings of note in a middle-aged man who presents with cough, fevers, and arthralgias.

These wounds occurred when this 77-year-old woman fell when chasing her dog. Such wounds-a combination of ecchymoses and erosion caused by blunt and sheering forces on fragile skin-are common in the elderly, even after relatively mild trauma. Simple interventions will promote healing.

These classic linear, wide-mouthed, red to purple, atrophic patches are classic for stretch marks (striae distensae). The patient was in the middle of his growth spurt.

The patient assumed that the itchy rash was due to insect bites. The shape, size, color, and presence of 6 legs of the insect he captured were consistent with bedbugs and bedbug bites.

The red patch on this woman's neck is lichenoid keratosis, a variant of seborrheic keratosis. Diagnostic contenders included Bowen disease and superficial basal cell carcinoma.

Both morphology and location favor the diagnosis of psoriasis. The presence of nail pitting, and a strongly positive family history for psoriasis, confirmed the diagnosis.

These widely scattered, dome-shaped pruritic inflammatory papules suggest insect bites. A biopsy showed mixed dermal infiltrate consisting of lymphocytes and eosinophils, consistent with an arthropod assault.

The differential diagnostic possibilities for this tender nodule included hypertrophic actinic keratosis, keratoacanthoma, squamous cell carcinoma, and verruca. The possibility of squamous cell carcinoma dictated removal with histologic examination.