Pruritic Papular Eruption (PPE)

Pruritic Papular Eruption (PPE) is a chronic intensely itchy skin condition strongly associated with HIV infection. It commonly occurs in patients with advanced immune suppression and may be the first presenting sign of undiagnosed HIV.

The disease results from an exaggerated immune reaction to insect bites or environmental antigens due to immune dysregulation.

Typical distribution:Extensor surfaces of upper and lower limbs (arms and legs), but may spread to trunk and face in severe disease.

Pathophysiology (Brief)

In HIV infection:

• Altered CD4 immune response

• Hypersensitivity to arthropod bites

• Persistent inflammatory reaction

Leads to:

• Chronic itching

• Recurrent scratching

• Hyperpigmented scarring

Severity correlates with low CD4 count

Signs & Symptoms

• Multiple papular lesions on extensor areas

• Severe persistent itching (often worse at night)

• Excoriations (scratch marks)

• Secondary infection may occur

• Healing leaves hyperpigmented scars

• Symmetrical distribution

Associated findings:

• Features of advanced HIV disease

• Weight loss

• Oral candidiasis

• Recurrent infections

Diagnostic Criteria

Clinical diagnosis based on:

• Papular lesions on extensor surfaces

• Severe pruritus

• Excoriations

• Healing with hyperpigmented scars

Investigations

PPE is mainly a clinical diagnosis, but evaluation for HIV and complications is essential.

Recommended tests

• HIV test (if status unknown)

• CD4 count (severity assessment)

• Full blood count

• Skin swab if secondary infection suspected

Optional

• Skin biopsy (if diagnosis uncertain)

Treatment

Non-Pharmacological Treatment

• Start or optimize antiretroviral therapy (ART)

• Avoid scratching (keep nails short)

• Daily bathing with mild soap

• Use emollients to restore skin barrier

• Wear protective clothing (long sleeves)

• Use insect bite prevention measures (bed nets, repellents)

• Manage secondary bacterial infection early

Pharmacological Treatment

Topical therapy

• Betamethasone valerate cream 0.025% — apply every 12 hours for 3–4 weeks

Systemic therapy (moderate–severe disease)

• Dapsone 100 mg once daily for 1 month

Additional supportive medicines (if needed)

• Oral antihistamines for itch

• Antibiotics if secondary infection present

Complications

• Post-inflammatory hyperpigmentation

• Secondary bacterial infection

• Sleep disturbance

• Psychological distress

• Marker of advanced HIV disease

Prevention

• Early HIV diagnosis and ART initiation

• Insect bite prevention

• Regular skin care with emollients

• Prompt treatment of new lesions

• Good hygiene practices