Pathology Clinic: Herpes Simplex Infection of the Pinna

A 40-year-old woman presented with a 9-month history of a painful right ear. The pain was experienced as superficial and had a burning quality, which interfered with sleep. She had no change in her hearing, no tinnitus or vertigo, no dysphagia, and her weight was stable. The patient’s past medical history was significant for previous diffuse large B-cell lymphoma of the bowel, which had presented with perforation requiring resection and subsequent short bowel syndrome, previous tuberculosis, and bronchiectasis.

On examination, there was extensive ulceration of the right pinna (Figure 1), involving the conchal bowl, root of the helix, and tragus, which was exquisitely tender. The external auditory canal was relatively unaffected, and the tympanic membrane was normal. Examination of the cranial nerves, oral cavity, and neck was unremarkable. Screening tests for HIV and hepatitis B and C were negative. A swab was taken for microscopy and culture which yielded Pseudomonas aeruginosa, with which the patient was known to be colonized. She was treated with oral and topical antipseudomonal therapy; however, this did not improve the patient’s pain nor the appearance of the lesion.

Figure 1.

Photograph of the right ear shows extensive ulceration of the pinna.

A punch biopsy of the conchal bowl was performed. This showed ulceration with loss of the epidermis and a dense mixed inflammatory infiltrate in the dermis. Within this, aggregates of “ground glass” inclusion bodies were seen, consistent with herpes virus infection. The bodies were positive for Herpes simplex immunohistochemistry (Figure 2). A second swab, sent on viral transport media, confirmed the presence of Herpes simplex type 1 DNA via polymerase chain reaction. The patient was treated with valacyclovir, with improvement of her pain and of the appearance of her ear.

Figure 2.

(A) Histological section, 400× magnification, hematoxylin and eosin stain, showing aggregate of viral inclusion bodies. (B) The inclusion bodies show positive herpes simplex 1 immunohistochemistry staining at 400× magnification.

Herpes simplex can infect any cutaneous or mucosal surface and is transmitted via skin-to-skin contact, particularly in abraded skin where the integrity of the stratum corneum is lost. ¹ Therefore, cutaneous eruptions of the face and ears are common in contact sports, where the condition is known as herpes gladiatorum. ² In this patient, there was no such history, and the severity of infection is unusual for an immunocompetent host.

The differential diagnosis of nonhealing ulcerative lesions of the pinna includes malignancy, infection, and vasculitides. If the diagnosis is unclear, or if there is failure of initial treatment, a biopsy should be performed. If viral infection is suspected, a swab should be sent in a tube of viral transport media for serological analysis.