Herpetic whitlow masquerading as pompholyx in a healthcare worker: revisiting the entity in today’s era

Herpetic whitlow masquerading as pompholyx in a healthcare worker: revisiting the entity in today’s era Dear Editor, Herpetic whitlow is a painful infection of the pulp and lateral aspect of the distal phalanx of the fingers caused by herpes simplex virus (HSV) 1 & 2. It is commonly seen in children and healthcare workers who are exposed to lesions of herpes which leads to inoculation. Few atypical presentations of this entity have been described, especially in the immunocompromised individual. Here we describe a case of herpetic whitlow presenting as pompholyx who was treated with immunosuppressants for 5 years. A 52-year-old female, working as a nurse in our hospital, presented with complaints of recurrent episodes of deep-seated vesicles involving the fingers on both hands over the past 5 years. These initially began as a few deep-seated blisters on her left little finger which were associated with itching. For these complaints, she was prescribed topical steroids and oral antibiotics. The lesions developed crusts within two weeks and resolved completely within 3 weeks. Since then, the patient has had multiple similar episodes involving bilateral thumbs and little and ring fingers. The frequency of episodes is almost four to five per year. She also complained of heaviness in affected limb along with burning in the fingers on affected side 1 to 2 days prior to the eruption. Over these 5 years, this patient had been treated by multiple dermatologists with oral acitretin, oral steroids, intravenous dexamethasone, and apremilast. The patient also took homeopathy and ayurvedic medications with no improvement. She was previously diagnosed as acrodermatitis continua of Hallopeau and pompholyx, was treated with steroids with minimal improvement, and experienced recurrence within 2–3 weeks of discontinuation. She did not have a past or family history of psoriasis or atopy. She did not give a history of allergy to latex or spirit. There was no past or family history of herpes labialis/gingivostomatitis/genitalis. When the patient presented to us, she had multiple deep-seated painful blisters on the pulp of bilateral thumbs with minimal erythema during the last 4–5 days. She also complained of malaise and burning for 2 days prior to eruption. On examination, there were multiple coalescing deepseated pin head-sized vesicles on the distal phalanx of the right thumb and was surrounded with minimal erythema (Fig. 1). The lesions were tender to touch. There was no lymphadenopathy or lymphangitis on examination. Tzanck smear examination from the floor of these vesicles revealed multinucleate giant cells (Fig. 2). Herpes simplex virus serology showed positivity for both IgM and IgG during the acute episode. Varicella zoster virus IgG was positive, but IgM was negative, which could be accounted for by history of varicella zoster in childhood. Cytomegalovirus (CMV) IgG & IgM were negative. Based on the above, we reached a diagnosis of herpetic whitlow. The patient was started on oral acyclovir 400 mg three times daily for one week, with symptomatic improvement within 48 hours and complete clearance within a week. However, she developed four such recurrent episodes within the next 2-1/2 months. Therefore, she had to be started on suppressive