Psoriasis and Canine Exposure Leading to Recurrent Prosthetic Joint Infection: A Case Report

Prosthetic joint infection (PJI) is a severe complication following total hip arthroplasty (THA), often requiring extensive medical and surgical intervention. This report presents a case of recurrent PJI associated with an untreated psoriatic lesion and habitual canine contact, highlighting an unusual yet significant vector for microbial transmission. A 51-year-old male patient underwent a primary total hip replacement in January 2024. Three weeks postoperatively, he developed a PJI caused by <i>Streptococcus agalactiae</i>. Despite a two-stage revision arthroplasty, recurrent infections were noted over the following months, with cultures later identifying <i>Staphylococcus aureus</i> and <i>Staphylococcus xylosus</i>. During hospitalization, the patient disclosed a longstanding psoriatic lesion on his knee, which he frequently scratched and allowed his dog to lick. Dermatological consultation confirmed psoriasis, and the association between his skin condition and bacterial transmission from his pet was suspected to contribute to the persistent infection. The patient demonstrated clinical and biological improvement following prosthetic revision and targeted dermatological management. This case emphasizes the importance of dermatological evaluation in patients undergoing joint replacement, particularly those with chronic inflammatory skin diseases such as psoriasis. Additionally, it underscores the need for thorough patient education on zoonotic bacterial risks. Recognizing the role of dermatological integrity and pet-associated bacterial transmission in PJI can enhance preoperative risk assessment and postoperative care strategies.