[Subcutaneous nodules of the head and neck heralding giant cell arteritis].

Background: Giant cell arteritis is the most common form of systemic vasculitis affecting individuals aged over 50 years. While its clinical manifestations are numerous, cutaneous involvement is uncommon and rarely constitutes the initial sign. We discuss a case of atypical skin involvement as the initial symptom of giant cell arteritis.

Observation: An 86-year-old woman presented purplish and painful subcutaneous nodules on the scalp and neck. Biological explorations showed systemic inflammation. The skin biopsy was evocative of polyarteritis nodosa. The nodules spontaneously disappeared completely, and asthenia and bitemporal headache gradually appeared. In view of the persistent inflammatory syndrome, a diagnosis of giant cell arteritis was proposed and was later confirmed by the temporal artery biopsy sample, with its typical histological appearance. Systemic corticosteroids resulted in complete regression of symptoms within a few days.

Discussion: To our knowledge, inflammatory cervical subcutaneous nodules have never been described in giant cell arteritis. The case we report herein thus raises the issue of differential diagnosis between various forms of vasculitis. While classification of the latter continues to progress thanks to improvements in physiopathological knowledge, the distinction between vasculitis of the large and small vessels remains tenuous on occasion. We discuss the differential diagnoses.

Conclusion: The dermatological presentation of giant cell arteritis in the present case suggests the existence of a continuum between small-, medium- and large-vessel vasculitis.