Sera from 23 patients with acne vulgaris of varying degrees and sera from 15 patients with skin diseases other than acne were tested for antibody levels to Staphylococcus epidermidis by use of bacterial agglutination and agar-gel immunodiffusion. Antibody levels to S epidermidis varied from 0 to 1:160 in both the patients with acne and in the control groups. There was no correlation between the antibody level to S epidermidis and the degree of acne.
In a previous investigation it was found that antibody levels to Corynebacterium acnes are significantly increased in serum from patients with papulopustular and cystic acne. Both S epidermidis and C acnes can frequently be isolated from lesions in acne. The fact that antibody levels are increased to C acnes but not to S epidermidis may indicate that the mere presence of an organism in the acne lesion is not sufficient stimulation for antibody formation. The increase of antibody to C acnes which was demonstrated previously in patients with severe acne vulgaris may therefore reflect a direct involvement of the organism in the acne process.