Clinical Guide > Comorbidities and Complications > Seborrheic Dermatitis

Seborrheic Dermatitis

January 2011

Chapter Contents

Background

Seborrheic dermatitis is one of the most common skin manifestations of HIV infection. It occurs in 3-5% of the general HIV-uninfected population but in up to 85-95% of patients with advanced HIV infection. Among HIV-infected individuals, seborrheic dermatitis often begins when their CD4 counts drop to the 450-550 cells/µL range. The disease is more likely to occur among young adults (because they have oilier skin) and males, and is more common in areas with cold, dry winter air. It is rarely found in African blacks, unless the person is immunocompromised. It is more common during times of mental stress and severe illness.

Seborrheic dermatitis is a scaling, inflammatory skin disease that may flare and subside over time. It is characterized by itchy reddish or pink patches of skin, accompanied by greasy flakes or scales. It most commonly occurs in the scalp and on the face, especially at the nasolabial folds, eyebrows, and forehead, but also may develop on the ears, chest, upper back, axillae, and groin. Dandruff is considered to be a mild form of seborrheic dermatitis. Occasionally, seborrheic dermatitis may be severe, may involve large areas of the body, and may be resistant to treatment. Severe manifestations are more likely with advanced HIV infection.

The etiology of seborrheic dermatitis is not entirely clear. Malassezia yeast (formerly called Pityrosporum ovale), a fungus that inhabits the oily skin areas of 92% of humans, is the most likely culprit. This same yeast also is thought to cause tinea versicolor and Pityrosporum folliculitis. Overgrowth of the Malassezia yeast in the oily skin environment, failure of the immune system to regulate the fungus, and the skin's inflammatory reaction to the yeast overgrowth appear to be the chief factors that cause the dermatitis.

S: Subjective

The patient complains of a new rash, sometimes itchy, or of "dry skin" that will not go away despite the application of topical moisturizers.

O: Objective

Perform a thorough evaluation of the skin with special attention to the scalp, medial eyebrows, eyelashes and eyelids, beard and other facial hair areas, nasolabial folds, postauricular areas, the concha of the auricle, glabella, umbilicus, central chest, back, axillae, and groin. Seborrheic dermatitis appears as white to yellow greasy or waxy flakes over red or pink patches of skin; however, discrete fine scales may indicate a mild form of the disease. Around the eyes, seborrheic dermatitis can cause eyelid erythema and scaling. The distribution usually is symmetrical.

A: Assessment

The diagnosis of seborrheic dermatitis is based on the characteristic appearance. A partial differential diagnosis includes psoriasis, atopic dermatitis, contact dermatitis, erythrasma, tinea capitus (can be present on the scalp without hair loss), rosacea, and rarely, dermatomyositis.

P: Plan

Treatment

Potential adverse effects:

Patient Education

References