Despite the photocarcinogenic properties of psoralen, it was used as a tanning activator in sunscreens until 1996. Psoralens are used in tanning accelerators, because psoralen increases the skin's sensitivity to light. Some patients have had severe skin loss after sunbathing with psoralen-containing tanning activators. Patients with lighter skin colour suffer four times as much from the melanoma-generating properties of psoralens than those with darker skin. Psoralens short term side effects include nausea, vomiting, erythrema, pruritus, xerosis, skin pain due to phototoxic damage of dermal nerve and may cause cutaneous and genital skin malignancies.