Dermatology

Pitted keratolysis is caused by pedal hyperhidrosis and subsequent overgrowth of bacteria that produce proteinases that dissolve keratin and lead to pit formation.

Most bruising episodes are directly related to trauma, medication, or herbal supplements. When no no clear etiology is prsent, "spontaneous" bruising should be considered an urgent problem.

Each of these lesions proved to be infiltrative basal cell carcinomas. Denial is a strong defense mechanism and it can lead patients to avoid seeking medical attention for long periods, as was the case here.

A small punch biopsy showed basal cell carcinoma with focal hypermelanosis. The underlying erythema and punctuate superficial dark black pigmentation strongly suggested a dysplastic nevus or even a melanoma.

This was presumed to be an ectoparasite bite when the patient reported that she had a new pet kitten. A myriad of diagnostic possibilities exist, including the start of a drug eruption or viral infection, early allergic contact dermatitis, or first manifestation of an autoimmune bullous disease.

These hypopigmented well demarcated round patches with an atropic center are typical of porokeratosis, which can appear at any age.

The easily visible 5 mm-long insect, is a classic bedbug (Cimex lectularis).

Epidermoid cysts may be treated with intralesional injections of phosphatidylcholine to avoid potential recurrence, eliminate scarring, and reduce cost.

A biopsy is the only way to determine if this is a primary cutaneous neoplasm or a cutaneous metastasis from a visceral carcinoma.

This woman is allergic to an ingredient in her favorite lipstick.

A biopsy is mandatory since the diagnosis includes melanoma. This blue-black macule proved to be a blue nevus.

Mammography showed a dense fine mass which, on fine needle aspiration, showed intraductal carcinoma.

A painful and/or tender subungual lesion should suggest a “glomus tumor”-- a benign growth seen more commonly in women than in men and most frequently under the fingernail.

A number of clues suggest that this pigmented lesion is a seborrheic keratosis, including its rough surface, truncal location, and age of the patient (59 years).

Leishmaniasis remains an important infection which can be “imported” from endemic foci, such as the Middle East.

Man with pruritic, edematous eruption of the upper and lower eyelids.

Hair loss: How to help your patients now - and what's on the horizon.

Nails: Tips when your patient complains “My nails look crummy!”

Psoriatic arthritis can be treated with the new TNF-alpha inhibitor biologic drugs, etanercept, adalimumab, or infliximab.

Eczema: how to keep patients disease-free after steroids. This video shows eczema and tells how to treat it.

This itchy, scaly rash extending from the underarm onto the upper arm was tinea corporis.

The tense bullae shown here and the chronicity of the disease should suggest the diagnosis of bullous pemphigoid.

Itchy skin. Is it hives? Scabies? Lichen planus? Or just an insect bite? Itching can also be psychogenic, or due to renal, hepatic, or thyroid disorders. Learn how to diagnose it in this video.

The almost black nature of the lesion arouses suspicion for melanoma. A conservative excisional biopsy revealed this to be a traumatic tattoo, however.

An 80-year-old-woman was seen as an inpatient hospital consult. A persistent pruritic eruption had developed acutely on the legs.