Sir.—The report of septic arthritis by Granoff et al (Am J Dis Child 132:488-490, 1978) interestingly reminds me of skeletal infections associated with Haemophilus influenzae type b. The value of cultures in these cases is obvious. However, I am concerned about the 28-month-old boy (second case) in whom documented H influenzae meningitis was followed in ten days by suppurative arthritis of the left elbow. No organisms were seen or recovered although antigen was detected by countercurrent immunoelectrophoresis (CIE). I believe three points should be borne in mind about this case.
First, there is the purported ampicillin susceptibility by agar disc diffusion method of this patient's isolate. Historically, this method of measuring susceptibility of H influenzae has lacked standardization. Thornsberry and Kirven1 have recommended an agar disc diffusion method that correlates with other susceptibility tests. It would be important for the authors to indicate the method used and/or zone
GRUNINGER RP. Possible Postinfectious Immune Arthritis: Haemophilus influenzae Type b. Am J Dis Child. 1979;133(3):332–333. doi:10.1001/archpedi.1979.02130030108027