Abstract: A study of 311 patients with polymorphous light eruption (PMLE) indicated that five subtypes were recorded as papulovesicles, small papules, large papules, edemadous erythema, and mixed rashes.Minimal erythema dose (MED) for both UVA and UVB were tested.Bivariate correlation analysis of all PMLE patients did not show a positive correlation between MED-UVA and MED-UVB as in the healthy controls.The MED-UVA and MED-UVB in patients with small papule subtype, and MED-UVB in edematous erythema subtype were significantly reduced which indicate that the clinical features and the action spectra are not the same in all PMLE subtypes.These results show that the term "PMLE" may still encompass several photosensitivity conditions with different pathogenetic mechanisms.

Key words: Polymorphous light eruption, Phototesting