To the Editor.—
In the May Archives (1980;116:517-518), Witkowski et al unduly criticized the article by Cook et al.1Lesion counting is a cumbersome, time-consuming, archaic method of measuring acne activity. Besides, data evaluation is difficult because most of the published clinical studies do not properly handle the statistics derived from lesion counting. For example, an investigator may count 50 papules on one visit and on the next visit may count 40 papules. The acne is somewhat improved. Should the change be expressed as a 20% reduction in activity or should it simply be stated as a reduction in the lesion count of ten? Another patient has ten papules and on the next visit has only five papules. Does this represent a 50% reduction in activity or simply a reduction in the lesion count of five? How the investigator handles these numbers obviously will greatly influence the statistical evaluation.
Samuelson JS. Acne Grading Methods. Arch Dermatol. 1981;117(5):252. doi:10.1001/archderm.1981.01650050006009