nail psoriasis

Definition : Psoriasis is the skin disease that most frequently affects the nails. Depending on the very nail structure involved, different clinical nail alterations can be observed.

Irritation of the apical matrix results in psoriatic pits.
Mid-matrix involvement may cause leukonychia.
Whole matrix affection may lead to red lunulae or severe nail dystrophy.
Nail bed involvement may cause salmon spots , subungual hyperkeratosis , and splinter hemorrhages.
Psoriasis of the distal nail bed and hyponychium causes onycholysis whereas that of the proximal nail fold causes psoriatic paronychia.

The more extensive the involvement, the more severe is the nail destruction.

A pustular psoriasis may be seen as yellow spots under the nail or, in case of acrodermatitis continua suppurativa, as an insidious progressive loss of the nail organ.

Synopsis

 ungueal psoriasis

• seen in up to 50% of psoriasis patients.
• more common in patients with psoriatic arthropathy.
• psoriasiform onychitis with spongiform pustulation, negative fungal special stains

Differential diagnosis :

 onychomycosis
 eczematous onychitis
 Reiter syndrome

Open references

 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5774607/