Onycholysis of the thumbs probably due to a phototoxic reaction from doxycycline.
Three members of a party climbing to the 18,640 foot level of Mt. Kilimanjaro in Africa experienced onycholysis or partial detachment of the thumbnails. It is believed that the combination of daily doxycycline administration and intense sunlight exposure resulted in a phototoxic reaction.
D000328:Adult; D004318:Doxycycline / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D009051:Mountaineering; D009260:Nail Diseases / Q000209:etiology*; D010787:Photosensitivity Disorders / Q000139:chemically induced*
D004318:Doxycycline