In Reply Dr Kak highlights the challenge of treating cellulitis given the lack of culture data and the possibility of using surrogate biomarkers instead. In patients with group A streptococcal infections, although the antistreptolysin O response usually appears within 1 week and peaks 3 to 6 weeks after the infection, the decline in titers is less well characterized,1 and elevated titers can persist long after initial infection. Also, many patients have recurrent bouts of cellulitis, which may further complicate titer results. These difficulties in interpreting a single antistreptolysin O titer led the World Health Organization to recommend that 2 assays performed 10 to 14 days apart with a 4-fold rise in titer between samples be used to diagnose recent group A streptococcal infection,2 which is impractical for patients with acute cellulitis.
Raff AB, Kroshinsky D. Therapy for Cellulitis. JAMA. 2016;316(19):2047. doi:10.1001/jama.2016.15613