In dermatology, as in other branches of medicine, it is often difficult to distinguish between similar diseases. Many of the laboratory procedures available at present do not offer diagnostic aid in such cases. We feel that the blood sedimentation test may give such aid in view of the general increase in the sedimentation rate in toxic, inflammatory and malignant conditions. It may be possible to differentiate such conditions as erythema multiforme bullosum, pemphigus and dermatitis herpetiformis. In dermatology, as in general medicine, the test should be used, not as a specific differential point in diagnosis, but as a general sign, which may differ in similar diseases or syndromes. The available literature on this subject in dermatology has been conflicting and unconvincing. For the most part, authors have reported on leprosy or syphilis. Studies in other diseases of the skin have been fragmentary and not sufficiently exhaustive.
TULIPAN L, DIRECTOR W. RED CELL SEDIMENTATION TEST IN DERMATOLOGYPRELIMINARY REPORT. Arch Derm Syphilol. 1933;27(5):759–765. doi:10.1001/archderm.1933.01450040768006