Photic sneeze reflex: When light becomes lethal

Photic sneeze reflex (PSR) is an autosomal dominant condition characterized by paroxysmal sneezing in response to bright light exposure. This is also known by the acronym ACHOO (Autosomal Dominant Compelling Helio-Ophthalmic Outburst) syndrome. Even though it has precipitated motor vehicle accidents (MVAs) leading to trauma, it remains yet as an underrecognized entity in emergency settings.

A 26-year-old male delivery boy who drives a scooter presented to ED with left periorbital swelling following an MVA triggered by PSR, while exiting a covered parking into sunlight. This was his third MVA in three months, all linked to photic transitions, with prior episodes causing vehicle damage only. He reported a three-month history of sneezing (10-15 bursts) triggered by sunlight and during tooth brushing, unresponsive to toothpaste changes. Examination revealed a left orbital floor fracture with inferior rectus entrapment, confirmed by CT scan. Allergy evaluation showed low total IgE (5 IU/mL) and negative specific IgE, ruling out allergic etiology. PSR was diagnosed and he underwent surgical repair, and received preventive counseling.

Life-threatening MVAs are likely to occur following PSR. In order to overcome such events, an early diagnosis, occupational counseling and prevention strategies are suggested. Emergency physicians should suspect light-induced sneezing, if vital signs are stable and the allergy workup is negative in such cases.