[Generalized granuloma annulare: A clinicopathological study].

BACKGROUND: Granuloma annulare (GA) is a benign granulomatous skin disorder that is generalized (GGA) in 15 % of cases. Although many case reports describe a relationship between GGA and systemic diseases, few large series have been published, and their association is debated. We present herein a series of GGA in order to describe their clinical and histological features.

PATIENTS AND METHODS: We included all biopsy-proven cases of GA presenting at the dermatopathology laboratory of Strasbourg where generalized (i.e. over 10 lesions). Clinical features were obtained from patients' medical files.

RESULTS: We included 35 GGA, with a sex ratio of 0.5. The mean age was 54 years. Lesions were annular or non-annular in equal measure and were symptomatic in 25 % of cases. Most patients (77 %) had an associated disease, already known in 60 % of cases, including dyslipidemia (27 %), diabetes mellitus (20 %), immunosuppressive drugs (17 %), atopy (17 %), auto-immune disease (17 %), hematological disease (14 %), and cancer (9 %). Histological analysis revealed the predominant pattern to be interstitial (54 %) rather than palisading (20 %), having no correlation with clinical type. Eosinophils were frequent (46 %) in GA but were not correlated with systemic disease or drug taking. Among the 40 % of patients treated, 50 % had a successful outcome on topical corticosteroids, doxycycline, antimalarial drugs or phototherapy.

DISCUSSION: GGA differs from localized GA, which is mostly associated with an already known systemic disease, whether metabolic, infectious or neoplastic, uncorrelated with clinical or histological features, and screening is necessary.