Vulvar herpes zoster infection: a rare and challenging diagnosis

Correspondence to Dr Matilde Matos Martins; [email protected]

Background

Herpes zoster is an infection which occurs when varicella zoster virus (VZV) is reactivated from its latent state in a posterior dorsal root ganglion. VZV usually affects the thoracic and lumbar nerves and their dermatomes (T3–L3), whereas sacral plexus herpes is extremely rare (4%–8%).¹ The involvement of the vulvar area is even rarer in sacral herpes. In the literature, very few cases of genital zoster have been reported in women. The use of molecular technology has allowed a reliable and unexpected diagnosis of genital zoster infections in female patients who present genital lesions.²

Herpes zoster infection frequently occurs in older patients and those infected with HIV, however, it is more frequent and severe in immunocompromised patients because their cell-mediated immunity is decreased.

Symptoms usually begin with a painful and erythematous papules rash along the affected dermatome, followed by a vesicular eruption which is usually diagnostic within 2–3 days. Grouped vesicles or bullae are the predominant manifestation throughout several days, and finally the rash becomes pustular within 3–4 days.

Lesions are typically unilateral and do not cross the midline of the body. Furthermore, the site is usually hyperaesthetic, and pain may be severe.³

Case presentation

This case report refers to a 26-year-old woman with Crohn’s disease and previous ileocolic resection, and who has been under immunosuppression with infliximab for the last 4 years. She was referred to our gynaecology emergency room due to the onset of vesicular lesions of varying dimensions on the vulvar region extending to the right lower limb associated with severe pain. Pain and skin lesions had started 4 days before admission to hospital.

No sexual risk behaviour was reported.

On examination, dispersed and coalescing vesicular lesions on an erythematous base of variable dimensions (5–15 mm) were seen on the right labium majorus and pubic mound forming blisters/bullae which extended to the homolateral inguinal region, medial and posterior thigh surface, and popliteal and plantar region. An ulcerative lesion was also visible on the right labium majorus medial surface (figures 1–3). There was no associated lymphadenopathy.

Investigations

Serological testing revealed:

• VZV IgG positive, VZV IgM positive.

• Herpes simplex virus type 1 (HSV-1) IgG negative, HSV-1 IgM negative.

• Herpes simplex virus type 2 (HSV-2)...