- Aetiology is uncertain - possible combination of environmental, genetic and immune factors.
- Nail changes are commonly found in patients with other signs of psoriasis and/or psoriatic arthritis and occasionally in those with no other skin manifestations of psoriasis.
- Incidence increases with age.
- Salmon patch: translucent yellow-red discoloration in the nail bed.
- Pitting of the nails, onycholysis, leukonychia.
- Dystrophic nail changes.
- Occasionally nail biopsy from the nail bed is needed to confirm the diagnosis.
- Potent steroid solution under occlusion may help.
- PUVA sometimes helps the nails as well as the skin.
- Intralesional triamcinolone every 4-6 weeks may help reduce pitting, leukonychia and ridging.
- Systemic methotrexate, retinoids or ciclosporin, but recurs after stopping treatment.
- Avulsion of the nail.
- Antifungal therapy if associated with fungal infection.
- Nail changes may develop with pompholyx or chronic eczema of hands and/or feet.
- Patients may have a genetic tendency to atopic eczema and/or pompholyx eczema.
- May result from outside factors such as stress, handling irritant substances, frequent immersion in water or contact allergies.
- May occur at any age. Usually patients have a history of long-standing eczema.
- Irregular transverse ridging.
- Pitting, thickening and discolouration.
- Other signs of eczema of the hands or feet affected.
- Usually a clinical diagnosis. Investigations not usually necessary except allergy testing and nail clippings to exclude fungal infection.
- Advise patients to avoid further use of any possible aggravating factors.
- Protect hands with cotton-lined rubber gloves when in water.
- Advise frequent use of emollients.
- Topical steroids - a potent one may be necessary for the hands and feet.
- Tacrolimus or pimecrolimus, azathioprine, methotrexate or ciclosporin.
- If the eczema improves, nails will usually return to normal.