The Holster Sign: An Overlooked Cutaneous Finding in the Diagnosis of Dermatomyositis

Abstract

Objective: Characteristic skin findings in dermatomyositis (DM) include Gottron’s papules (Gp), heliotrope rash (He) and shawl or V (S/V) sign. Noted in dermatology publications is a violaceous rash over the lateral hip, called the “Holster sign.� Our objective was to determine the incidence of the Holster sign (HS) in comparison to other DM cutaneous signs and to raise rheumatologists’ awareness of the HS. Methods: Patients with ICD-9 codes for DM, PM, MCTD and SS were identified. Patients received a survey that included pictures of He, Gp, S/V and HS and were asked to check if they “had any of the following skin findings?� Charts were reviewed to confirm the diagnosis and providers’ description of skin findings. We calculated the incidence rate, sensitivity and specificity of each skin sign for DM. Results: From 117 surveys, positive HS self-reporting was 22/28 in DM, 2/13 in PM, 0/21 in MCTD, and 6/55 in SS. Hs positive reporting of 78.5% in DM, was comparable to S/V (75%), Gp (85%), and He (71%). When compared to other signs, HS reporting was lowest in PM, MCTD and SS patients. Of all the skin signs, the HS had the highest specificity for DM (91%, range 75-91% for other signs) and comparable sensitivity (79%) to other signs (71-85%). Conclusion: This survey indicates that the HS has a comparable incidence to the more established and recognized cutaneous findings in DM. Based on these findings, we recommend looking for the HS sign in all patients with suspected DM.