Palmoplantar Pustulosis

Palmoplantar pustulosis is a complication of psoriasis. It affects the palms and soles. It is sometimes known as localised pustular psoriasis, when in occurs in those who have psoriasis elsewhere.

It is uncommon. Usually, but by no means invariably, it occurs in a person with pre-existing plaque psoriasis. It is rare before adulthood. The usual age to be affected is between 20 and 60 with women more often affected than men.

Risk Factors

It is much commoner in smokers or ex-smokers. There is a suggestion that it may be an autoimmune disease brought on by smoking.¹ It sometimes runs in families. The cause of exacerbations and remissions is unknown but stress may possibly be involved.²

• Groups of sterile pustules appear in crops on one or both hands. Alternatively they may appear on one or both feet or they may start on both hands and feet.
• Thickened, scaly, red skin develops and often fissures appear.
• The severity of the condition is highly variable.
• It may persist for many years.
• There is no adverse effect on general health but the discomfort can be considerable and interfere with work and pastimes.
• Prolonged walking may cause exacerbations on the feet. If the palms are involved, manual labour may be uncomfortable, and injuries may aggravate the disorder. This is probably a variation of the Koebner phenomenon.
• Occupations and hobbies should be chosen with care.

• Tinea pedis.
• Maceration of sweaty feet.
• Acropustulosis occurs on just the tips of the fingers.
• Pompholyx eczema

No specific investigations are required although it may be desirable to exclude fungal infection.

Treatment is aimed at palliation rather than cure.

General Measures

• Shoes should be comfortable, cool and made from natural fibres.
• Avoid friction and minor injuries.
• Cover deep fissures with a waterproof dressing.
• Rest the affected area.
• As it tends to be a disease of smokers, although not invariably, stopping smoking is to be advised but it does not always confer benefit.

Emollients

• Use thick emollients liberally to soften the dry skin to prevent fissures.
• Soak in warm water with emulsifying ointment for 10 minutes at least once a day.
• Apply white soft paraffin liberally.
• Salicylic acid ointment or urea cream can help to peel off dead skin but it may sting.
• Wash with bath oil or soap substitute.

Drug Treatment

• On an area as tough as the palms and soles, only the most potent topical steroid creams will be beneficial but, being so potent, they should be used for a limited time only. The effect can be enhanced by occlusion but it should not be used for more than 5 consecutive days.
• Crude coal tar is messy but effective. If applied directly to the pustules about once every 5 days, it can prevent recurrence. Apply accurately and cover. Mixture with an ointment base permits easier application.
• Calcipotriol ointment is applied twice daily. It is effective in some patients with psoriasis. It should not be covered. Hands should be thoroughly washed after application to prevent contamination of other parts of the body, especially the face.
• Acitretin is a vitamin A analogue. It comes in tablet form and can control palmoplantar pustulosis in the majority of cases. Adverse reactions can be severe and so it should be reserved for more difficult cases.
• PUVA can be very effective but careful supervision is necessary to prevent burning.

Other treatments that are less often used include:

• Colchicine
• Dapsone
• Methotrexate
• Tetracycline.

A Cochrane review³ was critical of the standard of evidence, as is so often the case. The authors felt unable to give definitive guidance on the best treatment for chronic palmopustular psoriasis but they drew the following conclusions:

• There is evidence supporting the use of systemic retinoids.
• PUVA is also effective.
• A combination of PUVA and retinoids is better than the individual treatments.
• The use of topical steroid under hydrocolloid occlusion is beneficial.
• It would also appear that low dose ciclosporin, tetracycline antibiotics and Grenz Ray therapy may be useful.
• Colchicine has a lot of side effects and it is unclear if it is effective.
• The benefit of topical PUVA is also unclear.
• There is no evidence to suggest that short-term treatment with hydroxycarbamide (hydroxyurea) is effective.

There is no risk to life but the condition is very uncomfortable and secondary infection in fissures can occur.

There is usually recovery in weeks to months but it can persist for years and may be recurrent. Acute and chronic forms probably represent the same disease but the prognosis for the acute type is so good that aggressive therapy is not recommended.⁴

It is rather less likely to occur in non-smokers, but sometimes it does so.