Coma blisters after a syncope episode

Abstract

We report a case of a 74-year-old man who developed an acute blistering eruption on both extremities after a syncope episode (for undetermined amount of time) with altered mental status. Tense and denuded bullae were found on non-blanching erythematous to violaceous skin involving the left forearm, left dorsal hand, left interdigital spaces, left upper chest and right medial knee. His medical history included diabetes mellitus, hypertension, end stage renal disease and a renal transplant 4 years ago. Patient did not have a history of similar skin lesions in the past. Skin biopsy revealed the development of an intraepidermal acrosyringeal bulla, accompanied by superficial, non-inflammatory purpura and stromal edema demonstrating the early stage of a coma blister before the characteristic onset of eccrine gland necrosis.

Coma blisters are self-limited cutaneous lesions characterized by tense bullae at sites of maximal pressure. They are diagnosed histologically by necrotic eccrine glands with minimal or absent inflammation. Although it occurs most commonly in the setting of coma with barbiturate overdose, they can be seen in coma due to other etiologies, or even occur in a conscious state.

Possible complications may include non-traumatic rhabdomyolysis and compression neuropathies, and may vary depending on patient‘s cause of unconsciousness and underlying medical conditions. Coma blisters look clinically alarming but they tend to spontaneously heal without specific treatment other than positional changes. In critical care settings where complex comorbidities exist, it is important to remember that coma blisters do not represent a contrain-
dication to continue any ongoing therapy.