A person’s fingernails or toenails can hold important clues in diagnosing psoriatic arthritis. Nail lesions occur in almost 90% of people with PsA. Researchers studying psoriatic arthritis noted that rheumatoid arthritis and psoriasis can occur together. However, the presence of 20 nail pits on a patient distinguishes them as having PsA instead of rheumatoid arthritis and psoriasis.
The results of a Canadian study of people living with PsA found that more than 90% of them had some kind of fingernail psoriasis on at least one nail. The study showed that patients with a crumbling nail or separation of the nail from the skin underneath it were more likely to have swelling or tenderness in the finger joint closest to that nail. They also found that people with blood spots under the nail tended to have higher numbers of swollen joints.
Pay attention to changes to your nails that might include:
- Crumbling nails
- Separation of the nail from the nail bed (onycholysis)
- Ridges and splitting in the nail (onychorrhexis)
- Spots of blood under the nail (splinter hemorrhages)
- Build-up of keratin between the nail and nail bed (subungual hyperkeratosis)