The Jarisch-Herxheimer reaction: revisited.

The Jarisch-Herxheimer reaction (JHR) is a transient immunological phenomenon seen commonly in patients during treatment for syphilis, and it manifests clinically with short-term constitutional symptoms such as fever, chills, headache and myalgias, besides exacerbation of existing cutaneous lesions. The complex interplay of its underlying patho-physiological mechanisms continues to elude modern medicine, ever since it was described over a century ago. An increase in the incidence of JHR may be expected among patients co-infected with HIV and other infectious diseases including syphilis. Since this subject has not received much attention in recent literature except for brief mentions in standard textbooks, we felt it important to provide an overview of its various attributes including the current concepts in pathophysiology and management.