Redness From Fire: Fevers, Abdominal Pain, and Rash

Abstract

Erythema ab igne (EAI) is an erythematous dermatosis that arises after repeated heat exposure. We present a case of EAI following chronic use of heating pads for analgesia. A 35-year-old woman with a history of familial Mediterranean fever (FMF), pancreatic exocrine insufficiency, presented to clinic for abdominal pain and fever. She presents to our GI clinic very frequently for FMF flares, which typically present as sharp abdominal pain with fevers, but this visit was unique for a new rash over her abdomen that was superficially nontender and nonpruritic. Over the years, the patient had been controlling her symptoms with colchicine, opioids, and heating pads. The abdominal exam was remarkable for mild tenderness to palpation diffusely, consistent with her previous flares. The overlying skin revealed a diffuse, nonblanching, hyperpigmented red/brown rash, sparing the periumbilical region and not extending into the flanks. Based on her well-known history, a diagnosis of EAI was made, and the patient was encouraged to avoid heating pads to that area. She has since decreased their use, and the discoloration persists but has improved.Erythema ab igne, or “redness from fire,” is a dermatosis that erupts on sites of repeated heat exposure. While historically associated with open fires, recent reports have implicated portable heaters, radiators, and even laptop computers. Two GI-related cases (gastroparesis and Crohn's disease), linked EAI with hot water bottles. The rash starts as a transient, reticulate, macular erythema, but with chronic heat exposure, becomes more livid and hyperpigmented. The heat is believed to cause superficial vasculature damage and dilation leading to erythema, and eventually, a more permanent hemosiderin and melanin deposition, which are presennt on biopsy and correlates to the darker hue. Usually, EAI resolves with avoidance of the causative heat source, although long-standing hyperpigmentation may persist for years. Reported treatments include topical 5-fluorouracil, bioflavonoids, trichloroacetic acid, and imiquimod. Biopsy is indicated if malignancy is suspected, as EAI has been rarely implicated in transformation into cutaneous squamous cell and Merkel cell carcinoma. Our case is particularly relevant to gastroenterologists since what can be an initially alarming abdominal rash that turns out to be a benign, self-resolving dermatosis, may at times end up serving as a clue for an underlying, more-serious GI issue.1852 Figure 1 No Caption available.