Psoriasis of the palms and soles

How does psoriasis affect the palms and soles?

Psoriasis may predominantly affect the palms and soles in various ways:

• Typical scaly, red patches similar to psoriasis elsewhere
• Generalised thickening and scaling of the palms and soles (keratoderma)
• Sheets of tiny yellow-brown pustules (palmoplantar pustulosis).

Palmoplantar psoriasis

More images of palmoplantar psoriasis ...

Clinical features

Palms and soles affected by psoriasis tend to be partially or completely red, dry and thickened, often with deep painful cracks (fissures). It can be quite hard to differentiate from hand dermatitis and other forms of keratoderma, but signs of psoriasis elsewhere may help make a diagnosis.

Palmoplantar pustulosis is considered a distinct entity in which there are clusters of pustules on the palms and/or soles, but about 10-20% of those affected have psoriasis on other sites of the body.

Palmoplantar psoriasis tends to be a chronic recurrent condition.

Treatment

Mild psoriasis of the palms and soles may be treated with topical treatments:

• Emollients: thick, greasy barrier creams applied thinly and frequently to moisturise the dry, scaly skin and help prevent painful cracking.
• Keratolytic agents such as urea or salicylic acid to thin down thick scaling skin. Several companies market effective heel balms containing these agents.
• Coal tar: to improve the scale and inflammation. Because of the mess, coal tar is often applied at night under cotton gloves.
• Topical steroids: ultrapotent ointment applied initially daily for two to four weeks, if necessary under occlusion, to reduce inflammation, itch and scaling. Maintenance use should be confined to 2 days each week (weekend pulses) to avoid thinning the skin and causing the psoriasis to become more extensive.

Calcipotriol ointment is not very successful for palmoplantar psoriasis and may cause an irritant dermatitis on the face if a treated area inadvertently touches it. Dithranol is too messy for routine use on hands and feet.

More severe palmoplantar psoriasis usually requires phototherapy or systemic agents, most often:

• PUVA
• Acitretin
• Methotrexate

Biologics are also sometimes prescribed for severe palmoplantar psoriasis.