What is palmoplantar pustulosis?

Palmoplantar pustulosis is an uncommon chronic pustular condition affecting the palms and soles. Palmoplantar pustulosis is also called pustulosis palmaris et plantaris. Palmoplantar pustulosis is related to a common skin condition, psoriasis. The skin develops tiny fluid filled blisters. They usually fill with a small amount of pus, turn brown, then scaly. The scaling may be so prominent that only redness and scaling is seen. The pustules are sterile pustules; there are no germs in them and they are not contagious. They come in waves or crops on one or both hands and/or feet. They are associated with thickened, scaly, red skin that easily develops painful cracks (fissures).

A variant of palmoplantar pustulosis affecting the tips of the digits is called acrodermatitis continua of Hallopeau or acropustulosis.

Certain conditions have been reported to occur in patients with palmopustular pustulosis more often than in unaffected patients.

• Chronic plaque psoriasis (10–25% of patients)
• Autoimmune diseases particularly gluten sensitive enteropathy (coeliac disease), thyroid disease and type 1 diabetes.
• Streptococcal tonsillitis.
• Rarely, synovitis–acne–pustulosis–hyperostosis–osteomyelitis (SAPHO) syndrome.

Palmoplantar pustulosis may rarely be provoked by the tumor necrosis factor (TNF)-alpha inhibitors (infliximab, adalimumab, etanercept).

Palmoplantar pustulosis occurs almost mostly in smokers (current or past), and it does not necessarily go away when the patient quits smoking.

Palmoplantar pustulosis sometimes runs in families and rarely occurs before adulthood.

Palmoplantar pustulosis is not caused by any known allergy or food.

Palmoplantar pustulosis varies in severity and may persist for many years. It is not known what triggers flare-ups. It has little effect on the health in general, but can be very uncomfortable. Usually, pressure, rubbing and friction will worsen palmoplantar pustulosis.

Palmoplantar pustulosis treatment does not cure the disorder, but the symptoms can usually be controlled. No treatment works for everyone. Some trial and error may be needed to find a successful treatment.

Superpotent topical steroid ointments (Temovate, Ultravate, Diprolene and Psorcon) applied overnight covered with Saran Wrap for a few days are often very helpful. Prolonged occlusion, in which a milder steroid is left, covered with a plastic bandage for 7 to 10 days, can be even more helpful. However these very potent products should be used only for limited periods or else skin damage and loss of effectiveness will become a problem. Once improved, an application of a moderately strong topical steroid can be applied twice daily to the affected area to maintain improvement.

Soaks in tar solution (Zetar emulsion or Balnetar) or crude coal tar and salicylic acid ointment (very messy) applied directly to the pustules every few days or so can stop them occurring or help peel off scale.

Tazorac gel or Dovonex ointments are very helpful to some patients alone, and increase effectiveness when added to other treatments. They can be irritating, but they don’t damage the skin as steroid ointments can.

Ultraviolet light, with or without an oral medication called oxsoralens (PUVA), is very effective for those who do not improve with creams and ointments. It is usually given in the doctor’s office three times per week. Burns, sometimes enough to blister the skin, occasionally occur.

Soriatane is an oral medication that helps control palmoplantar pustulosis in the majority of users. Unfortunately, there are many side effects. Most are not serious, but still it is only suitable for severely disabled patients. Cyclosporin is even more effective. Palmoplantar pustulosis will clear with just a fraction of the dose of cyclosporin used to treat other severe skin conditions. While safe for a short while, long term use is not recommended. Methotrexate is also used for severe palmoplantar pustulosis, with it’s own problems and side effects. Less reliably effective medications such as colchicine, tetracycline and dapsone are occasionally used.

Palmoplantar pustulosis causes

The exact cause of palmoplantar pustulosis is unknown. There have been several theories.

• It may be a disorder of the eccrine sweat glands, which are most numerous on palms and soles.
• Genetic factors are important as several members of some families are affected.
• It may be autoimmune in origin.
• Some cases have been associated with IL36RN gene mutations.

The majority of patients with palmoplantar pustulosis are current smokers and in those that have smoked in the past (65–90%). It is thought that activated nicotine receptors in the sweat glands cause an inflammatory process.

Palmoplantar pustulosis clinical features

Palmoplantar pustulosis presents as crops of sterile pustules occurring on one or both hands and feet. They are associated with thickened, scaly, red skin that easily develops painful cracks (fissures).

Palmoplantar pustulosis varies in severity and may persist for many years. The discomfort can be considerable, interfering with work and leisure activities.

Certain manual occupations or occupations involving much walking are inadvisable for affected individuals.

How is palmoplantar pustulosis diagnosed?

Palmoplantar pustulosis is generally diagnosed clinically.

• Laboratory tests for bacterial infection are negative.
• Skin biopsy may be helpful but is rarely necessary.

Palmoplantar pustulosis treatment

There is no cure for palmoplantar pustulosis. Treatment of palmoplantar pustulosis does not cure the disorder and is not always successful. The following may be helpful.

General measures

• If you smoke, try to stop: however, palmoplantar pustulosis may take several months or longer to improve.
• If you have celiac disease, follow a strict gluten-free diet.
• If you have recurrent tonsillitis, consult an otolaryngologist to see if a tonsillectomy is recommended.
• Choose comfortable footwear made from natural fibers.
• Avoid friction and minor injuries.
• Cover deep fissures with a waterproof dressing.
• Rest the affected area.

Emollients

• Use plenty of grease or other thick emollient to soften the dry skin to prevent fissures.
• Soak in warm water with emulsifying ointment for 10 minutes.
• Apply soft white paraffin liberally
• Use salicylic acid ointment, urea cream or a heel balm to peel off dead skin (this may sting).
• Wash using a bath oil or soap substitute.

Topical steroids

Topical steroids are anti-inflammatory agents which range in potency and vehicle. Only the strongest ointments are effective in conditions affecting the thick skin of the hands and feet. However, the very potent products such as clobetasol propionate should be used only for limited periods or else side effects and loss of efficacy become a problem.

A thin smear should be applied twice daily to the affected area. The effect may be enhanced by using plastic occlusion for a few hours or even overnight – use polythene gloves, plastic bags or cling film. Do not use occlusion for more than five days in a row.

Coal Tar

Crude coal tar is very messy but applied directly to the pustules every five days or so can stop them occurring. Paint on carefully and cover. It can be mixed in an ointment base for easier application.

Acitretin

Acitretin tablets, derived from Vitamin A, can control palmoplantar pustulosis in the majority of users. They have some potentially serious side effects so are only suitable for significantly disabled patients. A newer retinoid, alitretinoin, may also be effective.

Phototherapy

Narrowband UVB and photochemotherapy (the combination of exposure to ultraviolet radiation (UV-A) with psoralens taken as tablets or applied topically—bathwater PUVA—can be very effective. Careful supervision is necessary to avoid burning.

Other treatments

A variety of other medications can help some subjects including:

• Colchicine
• Dapsone
• Methotrexate
• Tetracycline antibiotics
• Ciclosporin

Although they sometimes induce palmoplantar pustulosis as a side effect of treatment, biologics are occasionally effective when used for severe palmoplantar pustulosis.