[Persistently crumbling nails in a patient with limited Dutch proficiency]

Nail psoriasis, also called psoriasis unguium, is a variant of psoriasis in which nail changes appear due to inflammation of nail bed or nail matrix. 15% to 50% of patients with cutaneous psoriasis have nail psoriasis, the condition also occurs without or before the appearance of skin lesions.

A 54-year-old male visits his general practitioner because of crumbling of his fingernails. Upon clinical examination, this was interpreted as onychomycosis and treated with oral antimycotics. Due to the lack of improvement and a negative PCR-test on dermatophytes, the condition was later diagnosed as nail psoriasis.

Nail psoriasis is often diagnosed as fungal infection of the nails. To make the right diagnosis, a complete medical history should be obtained, and physical examination of skin and joints need to be conducted. Furthermore, we advise to rule out onychomycosis in patients with known skin psoriasis to prevent overtreatment with antimycotics.