PT - JOURNAL ARTICLE AU - Alexander J Martin-Bates AU - Charles Martin-Bates AU - Richard Withnall TI - A diagnostic red herring AID - 10.1136/emermed-2017-206783 DP - 2018 Mar 01 TA - Emergency Medicine Journal PG - 184--184 VI - 35 IP - 3 4099 - http://emj.bmj.com/content/35/3/184.short 4100 - http://emj.bmj.com/content/35/3/184.full SO - Emerg Med J2018 Mar 01; 35 AB - Clinical introduction A 29-year-old keen parachutist presented to the emergency services in Cyprus complaining of sudden-onset facial flushing, dizziness and a widespread rash. The episode began on a hot day, 1 hour after she had eaten a breakfast of tinned tuna, and while she was ascending in an aircraft to parachute from 10 000 ft. She completed her jump uneventfully. She had no significant medical history (figure 1).Figure 1 Patient’s legs on presentation; this rash was generalised.Question Based on the history and rash, which ONE of the following is the most likely diagnosis?Fish allergyHeat-related eruptionScombrotoxin poisoningStress-induced urticariaQuestion