Exposure to light results in changes to the nails (Segal's triad):
(1) photosensitivity reaction
(2) discoloration of the nails
(3) onycholysis with separation of the nail from the distal nailbed
Baran and Juhlin (1987) recognized 3 patterns:
(1) Type I: half moon-shaped separation that is concave distally
(2) Type II: circular notch opened distally
(3) Type III: changes located in the central part of the nail bed, without connection to the margins
Sun-exposed skin may or may not show a photosensitivity reaction.
The presence of artificial nails, fingernail polish and gloves can protect the nails. However, they may also be used by the patient to mask the problem.
Drugs reported to be associated with photo-onycholysis include:
(1) doxycycline
(2) fluoroquinolones
(3) psoralen
(4) olanzapine
(5) aripiprazole
(6) indapamide
(7) quinine
plus many others
Photo-onycholysis may also occur in the cutaneous porphyries.
