A Case of Cowpox Presenting as Progressive Unilateral Facial Swelling and Fever Without Any Skin Lesions

Although a rare infection, sporadic human cases of cowpox do occur in endemic areas, often through contact with an infected cat. Cats are also incidental hosts but provide an important intermediary to the animal reservoir for cowpox, which in the United Kingdom (UK) includes bank and field voles.

We present a case of cowpox in an immunocompetent 25-year-old male who developed a progressive unilateral facial swelling over the course of 10 days associated with pyrexia. He never developed any lesions, nor did he develop any necrotising lymphadenitis as has been described in previous such cases without visible lesions. He had been exposed to his cat at a time when the cat only displayed eye disease and had not been exposed during the phase of the cat's illness when it had cutaneous manifestations. Both patient and cat made a full recovery.

Cases of cowpox in immunocompetent patients typically involve distinctive skin lesions at the site of the inoculation, but facial swelling with or without lymphadenitis can occur.