We read with great interest the letter published by Esteve-Martínez et al1 on nonsexually transmitted acute ulcer of the vulva, or ulcus vulvae acutum, associated with influenza A virus infection, and would like to congratulate the authors on their concise and thorough review of this condition.

We agree with their conclusion that it is important to be familiar with this type of vulvar ulcer and its association with influenza A virus infection,2,3 and would like to draw readers’ attention to fact that this ulcer can also occur in elderly patients, regardless of whether or not they report having had sexual relationships. One interesting case we saw recently was that of a 20-year-old woman with necrotizing genital ulcers that had required debridement in the gynecology department at our hospital.

The patient, with no relevant past history, reported that she had experienced fever and generalized joint pain 11 days before being seen in the dermatology department. She had been prescribed treatment with antipyretic medication and a single dose of oral levofloxacin by her primary care physician. Four hours after ingestion, the patient noted vulvar discomfort and an inflamed area. In the next 24hours, she also developed pharyngeal discomfort and a worsening general state of health, leading her to visit the emergency department, where a polymerase chain reaction (PCR) assay confirmed influenza A subtype H1N1 infection. The patient was admitted and treated with oseltamivir. During her stay in hospital, several deep, bilateral genital ulcers with necrotic-looking borders were noticed. Several swab specimens were obtained for standard culture, Neisseria gonorrhoeae culture, and PCR testing for Chlamydia trachomatis, herpes simplex virus types 1 and 2, and samples were taken for serology. Empirical treatment was initiated with ceftriaxone (single dose), oral acyclovir, and amoxicillin-clavulanic acid. The ulcers, however, continued to deteriorate and it was decided to debride the area. In view of the worsening condition of the patient, and the negative results for the viral cultures, the PCR tests, and serology for syphilis and human immunodeficiency virus (HIV), her physicians decided to request dermatologic evaluation.

At the time of this evaluation, there was marked vulvar edema and the posterior region of the right labia minora had been resected, leaving an ulcerated area with a clean base. On the left side of the vulva, there was a 1.5-cm exudative ulcer with a fibrinous base. The lesions were painful and accompanied by bilateral enlarged inguinal lymph nodes of less than 1cm. Topical treatment with absorbent dressings and fusidic acid was prescribed. The ulcers improved and began to heal within a few days; 3 weeks later, they had healed completely. Serology was negative for HIV I and II, syphilis, and cytomegalovirus. Epstein-Barr virus serology was negative for immunoglobulin (Ig) M antibodies and positive for IgG antibodies. No antinuclear antibodies were detected.

The differential diagnosis we considered included other causes of acute genital ulcer such as sexually transmitted diseases, lesions caused by trauma, complex aphthosis, and ulcerative lesions associated with autoimmune diseases or inflammatory bowel disease.4–6 In our case, the final diagnosis was ulcus vulvae acutum in association with H1N1 influenza A virus infection, although we cannot rule out the possibility that the drugs taken by the patient during her illness contributed to the aggressive course of the disease and the necrotic appearance of the lesions. There have been several reports of acute genital ulcers associated with influenza virus infection in the last 3 years, but it is not known whether this association is due to new mutations of the virus or to the concomitant ingestion of drugs. Prospective studies will help to determine whether the prevalence and course of ulcus vulvae acutum in patients with influenza differ depending on whether they receive oseltamivir or purely symptomatic treatment. Familiarity with this disease in emergency and dermatology departments will improve the management of these patients and prevent unnecessary interventions.