Pruritic papular eruption of HIV

What is pruritic papular eruption of HIV?

Pruritic papular eruption of HIV (Human Immunodeficiency Virus) is often reported as the most common rash seen in HIV infection. It is a form of prurigo. Anywhere between 18 and 46% of patients with HIV have this condition at some time. It can be very distressing for patients as it can be disfiguring and stigmatising. Often treatment is disappointing.

What causes pruritic papular eruption of HIV?

Strictly this rash is a diagnosis of exclusion, when all other causes have been ruled out. This means that currently there is no identified cause. Arthropod bites, medications, autoimmunity and direct HIV infection of the skin have all been considered, but not proven.

Unfortunately many reports in the literature include a number of other conditions under the heading of pruritic papular eruption of HIV. These include

• Folliculitis
• Staphylococcus infections
• Malassezia infections
• Eosinophilic folliculitis
• Herpes simplex virus infections
• Pseudomonas infections
• Infection with Gram negative rods (eg Klebsiella, enterobacter)
• Demodicidosis
• Insect bite reactions
• Granulomas
• Granulomatous drug reactions
• Lichenoid and granulomatous dermatitis of AIDS
• Post viral granulomatous reaction
• Acne

It is necessary to consider and exclude these other conditions before a diagnosis is made. In most cases a skin biopsy is required.

What are the signs and symptoms?

Pruritic papular eruption of HIV is nearly always a very itchy rash. It presents as multiple discrete scratched red bumps, which are symmetrical and diffusely distributed. The extremities and trunk are affected more than the face. The mucous membranes (mouth, nostrils, eyes, genitals), palms, and web spaces are spared.

It is the presenting symptom of HIV in 25-79% of cases. It is also a skin sign of advanced HIV, being three times more common when the CD4 lymphocyte count is less than 200 x10⁹/L.

What treatments are available?

Unfortunately pruritic papular eruption of HIV often proves very resistant to treatment. However, there are a number of different treatment approaches that have been shown to be effective in at least some patients.

Topical steroid, emollients and oral antihistamines should be the first line approach, because of their availability and safety.

Failing this phototherapy (UVB or PUVA) should be commenced. This is usually effective. The average time for the skin condition to recur is 8 weeks.

Another reported useful agent is oxpentifylline. This is thought to be work by its TNFα inhibitor effect. The usual dose is 400mg three times daily for at least 8 weeks.

Whether HAART (Highly Active Anti-Retroviral Therapy) makes a difference is debated and the response is variable. But because some people have seen consistent responses, there has been a recommendation that pruritic papular eruption is used as qualification for initiating HAART.