Onycholysis

The distal separation and loosening of the nail plate from the nail bed, typically starting at the free edge and progressing proximally. Possible causes are trauma, moisture/irritants, fungal infection (onychomycosis), bacterial infection, psoriasis, eczema, contact dermatitis, drug-induced photosensitivity (tetracycline), iron deficiency anemia, hypothyroidism, hyperthyroidism, or diabetes.