Dermatology MCQ - Viral Infections - Papular-pruritic gloves and socks syndrome

A 22-year-old woman presents with an acute, intensely pruritic eruption characterized by erythematous papules and petechiae sharply confined to her hands and feet. She also has oral erosions and a mild fever. The rash appeared abruptly after a recent upper respiratory infection. A serum PCR is most likely to detect which of the following viruses?

A) Parvovirus B19
B) Herpes simplex virus type 1
C) Epstein-Barr virus
D) Hepatitis B virus
E) Coxsackievirus A6

Correct Answer: A) Parvovirus B19

Explanation

This presentation is classic for papular-pruritic gloves and socks syndrome (PPGSS), a distinct viral exanthem.

Key Clinical Features of PPGSS:

• Distribution: Sharply demarcated erythema, edema, and papules on the hands and feet (glove-and-sock distribution). Petechiae may be present.

• Symptoms: Intense pruritus and burning pain are characteristic.

• Mucosal Involvement: Oral erosions (enanthem) on the palate, pharynx, and buccal mucosa are common.

• Systemic Symptoms: Low-grade fever, malaise, and lymphadenopathy may accompany the rash.

• Timing: Acute onset, often following a prodromal illness.

Virologic Association:

• Primary Cause: Parvovirus B19 is the most frequently identified pathogen associated with PPGSS.

• Pathogenesis: The rash is thought to result from a cell-mediated immune response to the virus, leading to a widespread cytotoxic reaction and endothelial damage.

• Diagnosis: Serum PCR for parvovirus B19 DNA is highly sensitive during the acute phase. IgM antibodies may also be detected.

Why Not the Other Options?

• (B) Herpes simplex virus type 1: Causes herpetic whitlow (vesicles on fingers) or gingivostomatitis (oral ulcers), but not a symmetric, glove-sock distribution rash.

• (C) Epstein-Barr virus: Causes infectious mononucleosis with pharyngitis and a generalized maculopapular rash (if amoxicillin is given), but not a acrally distributed pruritic papular eruption.

• (D) Hepatitis B virus: Can cause serum sickness-like syndrome (urticaria, arthritis) but not PPGSS.

• (E) Coxsackievirus A6: Causes hand, foot, and mouth disease (vesicles on hands, feet, mouth), but the lesions are vesicular and not typically pruritic or petechial.

Management:

• Supportive care: Antihistamines for pruritus, topical corticosteroids for inflammation, and analgesics for pain.

• Self-limiting: The eruption typically resolves within 1-2 weeks without sequelae.

Prognosis:
Excellent; PPGSS is a benign, self-resolving condition.

Note: PPGSS is a clinical diagnosis supported by virologic testing. The glove-and-sock distribution is pathognomonic. Always consider parvovirus B19 in this presentation, as it is the most common causative agent.