Early Recognition and Successful Treatment of Acquired Idiopathic Generalized Anhidrosis in a Deployed Servicemember

Acquired Idiopathic Generalized Anhidrosis (AIGA) is a rare but potentially debilitating condition characterized by sudden loss of sweating without an identifiable neurologic or structural cause. A previously healthy 31‑year‑old active duty male presented with an acute onset generalized anhidrosis that rapidly progressed to near complete body involvement, severely limiting his ability to perform in a heat‑intensive operational environment. Punch biopsies from the left arm and lower back demonstrated superficial and deep periadnexal lymphocytic infiltrates. Immunostaining with Tryptase, CD117, and CD3 highlighted periadnexal mast cells and lymphocytes, supporting the diagnosis of AIGA. Given the broad differential for anhidrosis-including sympathetic pathway dysfunction at multiple levels-skin biopsy can be an important diagnostic tool. AIGA predominantly affects young, active males and significantly impairs heat tolerance, posing particular risk to athletes and military personnel who rely on intact thermoregulation. Prior reports describe favorable responses to systemic corticosteroids, especially when initiated early. Our patient was treated with systemic steroids and experienced rapid restoration of sweating and full return to duty within weeks. This case underscores the importance of recognizing AIGA as a rare yet highly treatable condition and highlights the value of timely clinicopathologic correlation to restore function in operationally essential personnel.