Dermatology

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.

A multiplicity of colors in a pigmented lesion usually dictates the need for a biopsy. In this woman with many nevi and a history of malignant melanoma, biopsy revealed an inflamed blue nevus and was also curative.

The development of eccentric pigmentation within a previously stable pigmented lesion may indicate malignant degeneration, as was the case here. Of all melanomas, lentigo maligna melanoma has the best overall prognosis.

Round plaques like this one, each composed of many small erythematous papules, are classic for granuloma annulare. Large numbers of these lesions and widespread distribution is often associated with diabetes mellitus.

Sebaceous hyperplasia are commonly mistaken for basal cell carcinoma. These small papules with a yellowish hue and central dell is typical of the former, for which no treatment is required.

Biopsy of this red, scaly patch showed in situ squamous cell carcinoma. Treatment consisted of once-daily topical application of 5% imiquimod until erosion occurred. This off-label treatment affords an excellent cosmetic result.

These small areas of white dyschromia are typical of white superficial onychomycosis, often due to dermatophyte invasion following minor trauma. This form of onychomycosis usually responds well to topical therapy.

This is a prototypical case of acute contact dermatitis to benzoyl peroxide that the patient had been applying for her mild to moderate papulo-pustular acne. Twice-daily application of hydrocortisone 2.5% cream led to prompt resolution of the rash.

Biopsy of the flat area of this erythematous patch revealed superficial basal cell carcinoma while biopsy of the more nodular component revealed deeply infiltrating basal cell carcinoma.

This non-tender, freely mobile, rubbery-feeling nodule is a classic lipoma. Diagnostic contenders include epidermal cyst and cutaneous metastases.

Eccentric and irregular pigmentation prompted a biopsy in this elderly woman with a history of basal cell carcinoma and melanoma. The surprising diagnosis was a heavily pigmented squamous cell carcinoma in situ.

The puncta, with a black center, clearly identified these as classic epidermal cysts.

Biopsies of this large variegated pigmented plaque ruled out lentigo maligna melanoma and gigantic seborrheic keratosis.

This translucent dark pink nodule located just behind the nail is the classic presentation of a digital myxoid cyst.

After a dog bite, trauma in the form of a subungual hematoma and shallow lacerations prompted a 10-day course of amoxicillin-clavulanate. This antibiotic is also useful for cat and human bites that appear to be at high risk of becoming infected.