ABSTRACT
Phototesting is simply a determination of a patient’s level of reactivity or sensitivity to a given waveband or wavebands of radiation. The most common end point is the development of delayed erythema but sometimes other end points may be used such as development of a rash, immediate erythema, or pigmentation. Phototesting is an essential component of safe and effective delivery of phototherapy and photochemotherapy but unfortunately, many practitioners skip this step to the detriment of overall patient care.
