(657) Coma Bullae and Rhabdomyolysis in a Patient With Autism and Hypercapnic Respiratory Failure

Introduction: Coma bullae are pressure site bullous lesions that appear in patients with altered sensorium due to toxic encephalopathy or neurologic disorders. It has been described in patients with alcohol or drug intoxication, especially barbiturates. It may be confused with similar skin conditions such as cellulitis and contact dermatitis.

Description: A 50-year-old male with a history of nonverbal autism, ankylosing spondylitis, class III obesity and seizure disorder was admitted to the ICU with hypercapnic respiratory failure and rhabdomyolysis, with a CK of 40,169mg/dl. He had erythema and several blisters on the medial and lateral regions of his right forearm, which was firm to touch, raising concern for compartment syndrome. He was placed on non-invasive ventilation. Intravenous hydration was started and broad-spectrum antibiotics were initiated due to concern for necrotizing fasciitis. He had preserved pulses, sensation and motor function of his right forearm. His rash didn’t progress in the next days. He was having frequent falls and worsening mobility at home. Dermatology consultation was obtained, and a diagnosis of coma bullae was established based on the history of likely prolonged immobility over his right forearm, leading to significant muscle breakdown and subsequent rhabdomyolysis. His BMI was 47 and he was receiving lorazepam as needed for anxiety at home, all of which, along with his ankylosing spondylitis, could have contributed to his altered mental status and prolonged immobility. Antibiotics were discontinued and local wound care was provided with gradual improvement of the lesions.

Discussion: Recognizing coma bullae as a differential diagnosis for new onset bullous lesions in patients with altered mental status is important as diagnosis is clinical and treatment supportive. Onset is approximately 48-72 hours after onset of mental status change leading to prolonged immobility. Locations not under pressure may also be involved. The blisters are tense on a background of either a clear skin or an erythematous plaque. Contents may be clear or yellowish fluid or hemorrhagic. Biopsy may be performed to exclude other dermatologic conditions. Blisters resolve spontaneously in 2-4 weeks. Treatment is local wound care and pressure offloading.