Atypical Hidradenitis Suppurativa Involving the Posterior Neck and Occiput

We describe 4 patients who were seen between 2010 and 2011 with a unique presentation of hidradenitis suppurativa (HS) involving the posterior neck or occiput. Diagnosis was based on the morphologic characteristics of inflammatory nodules and sinus tracts as well as a history of failed treatment with antibiotics and isotretinoin in all patients. Dissecting cellulitis was ruled out owing to either lack of scalp involvement or only segmental scalp involvement.

A 27-year-old healthy white man presented with a 17-year history of HS distributed mainly on the nape of his neck but also involving his axillae bilaterally. Inflamed nodules and atrophic scarring along the posterior aspect of his neck were noted on physical examination (Figure 1).

A 33-year-old white man presented with a 14-year history of HS involving the jawline and posterior neck. On physical examination, severe cribriform scarring and sinus tracts were noted along his jawline. Erythematous papules and nodules were present on the jawline and occipital scalp with associated scarring hair loss.

A 49-year-old white woman presented with a history of “itching and scale ” behind both ears. On physical examination, multiple draining sinus tracts and erythematous nodules were noted in the posterior region of both ears (Figure 2).

A 17-year-old white man presented with a 5-year history of HS primarily on the back of his neck but with involvement also of his axillae and groin. On physical examination, a crusted nodule on the posterior occiput as well as several scarred areas and sinus tracts were found. Hyperpigmented macules and scarring were present in the left axilla and groin.

Patients 1, 2, and 3 reported a history of current or past tobacco use, and had a body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) below 25. Patient 4 did not report a history of tobacco use but reported a BMI of 36.

Hidradenitis suppurativa is a disfiguring and debilitating disease characterized by chronic and recurrent inflammatory nodules that typically occur in the body folds. However, HS can occasionally occur in atypical locations such as the face, ears, back, and neck. To our knowledge, there have been only 3 reported cases of HS in the posterior neck: a case of severe HS,¹ a case from a series otherwise describing perianal HS,² and a case report of a patient treated with a radiofrequency device.³ The diagnosis of HS accounts for both morphologic characteristics and distribution of lesions, and yet cribriform scarring and sinus tract formation were noted outside of typical areas in our patients.

There was also a lack of associated comorbidities in our patients. Hidradenitis suppurativa is commonly associated with obesity,⁴ yet only patient 4 had a BMI over 25. All other patients, however, had a history of tobacco use. Smoking is a risk factor commonly associated with HS, with some studies suggesting that tobacco is a trigger for HS.⁵

In our clinic, we see over 200 patients with HS per year, and although our series involved only 4 patients with this atypical presentation, we believe that physicians should be aware of this interesting variant of HS. It is important for practitioners to recognize that HS may occur on areas of the body not commonly associated with the condition.