Phototoxin

Phototoxins are toxins that can cause allergic reactions in particularly susceptible individuals and which can cause dangerous photosensitivity in a much broader range of subjects.

Phototoxins are common in:

Ingested medications may cause systemic photosensitivity and topically applied medications, cosmetics and essential oils may lead to local (or perhaps systemic) photosensitivity. Curiously and ironically, para-aminobenzoic acid (PABA) found in some sunscreens can also cause photosensitivity.