Psoriasis - Nail and Distal Digit
The most common nail findings in psoriasis are pitting, nail plate yellowing, onycholysis, subungual hyperkeratosis, splinter hemorrhages, and "oil spots." Psoriasis may also involve the nail folds in the form of swelling and chronic paronychia. Toenail findings are less frequent than psoriatic changes in the fingernails. When they do occur, subungual hyperkeratosis and yellow discoloration of the nail plate are the predominant findings.
Pediatric Patient Considerations:
Nail psoriasis in children is associated with more severe disease in most studies. It may be more common in boys than girls. The prevalence of nail psoriasis in children is 15%-19%. Furthermore, psoriasis is believed to be the cause of 7%-40% of all nail dystrophies seen in children.
L40.0 – Psoriasis vulgaris
9014002 – Psoriasis
Differential Diagnosis & Pitfalls
- Reactive arthritis (Reiter syndrome)
- Lichen planus
- Alopecia areata – Pits are generally more superficial and regular.
- Pachyonychia congenita
- Pityriasis rubra pilaris
- Idiopathic trachyonychia
- Other causes of onycholysis (eg, autoimmune diseases, medications, trauma)
- Atopic dermatitis – If there is eczema that involves the proximal nail folds, abnormalities in the nails may be seen, including coarse pits and nail dystrophy.
Drug Reaction Data