The early bird and the worm: a case of cercarial dermatitis
A 36-year-old man presented to our dermatology department with a 5-day history of an intensely pruritic papular eruption on the dorsum of both feet, associated with significant swelling and discomfort. This began the morning after a night-time fishing trip on the central coast of New South Wales at the mouth of the Lake Tuggerah estuary, a system of brackish tidal estuaries.
The patient reported standing ankle-deep in water for 6 hours from dusk (9 pm) until early morning (3 am). He noted that the water was particularly warm after a daytime temperature of 33°C with seaward tidal flows. He awoke the following morning with multiple discrete nodules, oedema and intense pruritus to the dorsa of the feet. He reported previous episodes of “bites” after fishing trips that spontaneously resolved after 24–48 hours.
The next 12 hours saw an increase in pruritus and the size of lesions. The patient presented to a general practitioner, who diagnosed pelican itch with secondary infection and prescribed cephalexin 500 mg four times a day for 5 days. Pain and pruritus continued to increase, resulting in the patient presenting to a metropolitan emergency department where he was diagnosed with bilateral foot cellulitis and administered intravenous cefazolin 1 g twice daily for 5 days. Investigations showed leucocytosis (white cell count, 10.1 × 109/L;…