Skin conditions have unique facade in HIV patients

Skin & Allergy News, June, 2007 by Jane Salodof MacNeil

PHOENIX -- Though less common with antiretroviral therapy, skin problems still occur in patients infected by human immunodeficiency virus and can present in unusual ways, Dr. Guy E Webster said at a clinical dermatology conference sponsored by Medicis.

Warning that "diagnostic parsimony in HIV may lead to error," he urged clinicians to consider multiple diagnoses in patients with low T-cell counts.

"It is typical to see two or three infections," said Dr. Webster of Thomas Jefferson University, Philadelphia.

Atopic dermatitis usually presents as typical eczema and receives standard care, he said. HIV-positive patients are also likely to have Staphylococcus superinfections, however, and these need to be treated aggressively.

Itchy bumps on the upper chest and head of an HIV-positive patient are a sign of eosinophilic pustular folliculitis, a condition of unknown etiology. Dr. Webster suggested steroids, ultraviolet B light, and possibly itraconazole as treatments.

Molluscum often presents with unusually large, "exuberant" lesions that can look like warts or basal cell carcinoma, he noted. Persistence is crucial, as treatment will take longer than in other patients. Consider liquid nitrogen, trichloroacetic acid, and curettage.

Psoriasis is not more common than in non-HIV patients, but Dr. Webster said it can be redder and more severe, with yellow scale. Topical therapies are less useful when the patient is HIV positive, but acitretin, ultraviolet B light, and cyclosporine can help. "Getting the T-cell count up is most important," he said.

Fungal infections should also be considered, not only candidal infections such as thrush and intertrigo but also dermatophyte (in particular, Majocchi's disease) and atypical yeast infections. Histoplasmosis and Cryptococcus may mimic molluscum or folliculitis, he warned, and urged physicians to "watch for the outlier patient."

Syphilis looks the same in an HIV-positive patient but behaves differently from its normal course. It may progress more rapidly, so "we overtreat, figuring the stage may be more advanced than the appearance," he said.

Ulcers can have many causes. Even if the physician considers an ulcer to be minor, it should be taken seriously when a person is HIV positive. Dr. Webster described one patient who became despondent and was convinced that he was going to die until an ulcer was successfully treated. "In chronic patients, little things can make a big difference," he said. When dealing with atypical herpetic ulcers, biopsy is the best way to diagnose cytomegalovirus infections. Mycobacterial ulcers are best treated surgically, he added.

Bacillary angiomatosis is not as common as it once was in HIV-positive patients, but it still occurs and should be considered in patients who present with ulcers, papules, or nodules and have cats at home. Dr. Webster estimated that 9 of 10 cases are caused by Bartonella henselae infection, the source of cat-scratch disease. The rest are caused by Bartonella quintana, which is transmitted by body lice.

"You have to diagnose by suspicion," he advised, warning that most pathologists will not spot B. henselae unless told to look for it in a biopsy specimen or titers (culture is not recommended). Treat the patient with doxycycline while awaiting the results.

Watch for edema when treating Kaposi's sarcoma in an HIV-positive patient. It can contribute to ulceration. If treating with radiotherapy, be sure the oncologist will not overdose the patient. "You need an oncologist who understands you are not treating cancer. You are treating a viral infection," he said.

Liquid nitrogen and intralesional vinblastine are also effective, he added. Liquid nitrogen costs less and works well on isolated lesions but can scar. Intralesional vinblastine is expensive and painful, but it may clear lesions without scarring.

BY JANE SALODOF MAcNEIL

Senior Editor