When horse serum meets dog bite

Abstract

A 61-year-old woman visited our clinic to continue rabies post-exposure vaccination. She had sustained a dog bite on the right calf during a journey to South Asia seven days earlier. Immediately after the bite she received several injections on both upper arms, as well as around the bite site, at a local clinic. Active immunisation with Verorab®, intradermally applied at both deltoid areas on days 0 and 3, was documented on the vaccination card. Passive immunisation was not recorded. Simultaneous to post-exposure immunisation she was started on oral amoxicillin–clavulanic acid for 10 days. When we saw her on day 7 she presented with a well demarcated, slightly raised, warm, puritic, and painless erythema posterior to the bite site (Fig. 1A) and an identical lesion at the lateral thigh of the same leg (Fig. 1B). Considering ongoing antibiotic treatment and the distance of the two lesions to each other and the bite site, bacterial soft-tissue infection was unlikely. On inquiry the patient recalled an intra-dermal injection into the flexor surface of the right forearm approximately 15 min before receiving the injections around the bite site and the right thigh. This “sensitivity testing,” as well as the raised eosinophil count of 8% (WBC 8.1 × 103 μl−1), led us to conclude that this was a local hypersensitivity reaction to equine rabies immunoglobulin. The two skin lesions resolved spontaneously over the next 7 days. Fig. 1 (A) Right calf and (B) right thigh.