A boy in his teens with large ulcerations of the head and neck.

Background: Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis, has a predilection for the upper airways, lungs and kidneys. However, any other organ can be affected. Although cutaneous lesions are common, they have only rarely been reported as a primary manifestation of the disease.

Case presentation: We present a case of a teenage boy with pyoderma gangrenosum-like ulcerations of the neck and face. Anti-neutrophil cytoplasmic antibody with antigen specificity for proteinase 3 (PR3-ANCA) was detected. In the absence of other symptoms and organ manifestations, the ulcerations were still considered to be pyoderma gangrenosum. The ulcers started to heal during treatment with corticosteroids and infliximab. One month later the patient developed sinusitis, and eventually lost vision in his left eye. The diagnosis was changed to GPA and he started treatment with methylprednisolone, rituximab and cyclophosphamide with good response on vision, sinusitis and ulcerations.

Interpretation: Recognition of this rare skin presentation of GPA is essential, to prevent delays in diagnosis and treatment that can lead to organ damage.