What Is Palmoplantar Pustulosis?

Palmoplantar pustulosis (PPP) is a rare skin condition that’s hard to treat. It involves eruptions of sores called pustules on the palms of your hands or the soles of your feet.

Pustules are blisters filled with a cloudy liquid. They can be itchy, painful, and cause a burning sensation. Some cases are severe enough to be debilitating.

This article walks you through the symptoms and causes of PPP, plus how it’s diagnosed and treated.

Symptoms of Palmoplantar Pustulosis

The severity of PPP varies greatly from person to person. It can go on for years, and so far researchers don’t know what makes it flare. Symptoms of PPP can include:

• Formation of pustules that may turn brown or scaly
• Itching, burning, or pain
• Recurring breakouts, sometimes over many years

Pressure, rubbing, or friction can make the symptoms worse.

After the pustules form, they may combine and form an area of red, thickened skin called an erythematous background, with scaly spots called plaques. The skin may also develop painful cracks.

Since PPP primarily affects the hands and feet, the discomfort caused by the condition can prevent you from walking or using your hands. 

Causes

Experts don’t yet know the exact causes of PPP, but it may be a disorder of the sweat glands. You have several of those on your palms and soles.

PPP is more common in people with psoriasis. It may involve autoimmune or autoinflammatory processes, where your immune system mistakenly attacks healthy cells.

Research shows that the condition is associated with:

• Smoking: Nicotine may trigger sweat gland inflammation that leads to pustules.
• Bacterial infections: Tonsillitis and dental infections may trigger outbreaks that go away when the infection is gone.
• Biologic medications: This class of drugs, especially TNF blockers, may cause pustules by activating a portion of the nervous system. These drugs are used for inflammatory conditions like psoriasis and rheumatoid arthritis.
• Contact allergies: PPP is more common in people allergic to nickel, chromium, mercury, and some fragrances. Avoiding the allergen may help clear an outbreak.
• Genetics: You’re more likely to have PPP if you have a family history of it or of psoriasis.
  

Diagnosis

A healthcare provider may be able to diagnose PPP on sight. They may take swabs to confirm that the blisters don’t contain pathogens (e.g., bacteria, fungi).

If the diagnosis isn’t clear, they may perform a biopsy, but this is uncommon. During this procedure, a small skin sample is removed and sent to a lab for analysis.

Treatment

Treatment options for PPP may include:

• Topical steroids
• Moisturizers
• Topical retinoid medications (retinol, tretinoin, bexarotene)
• Phototherapy with ultraviolet light

Some of these therapies may be used together. In severe cases, immunosuppressive drugs may help. The first-line medications for PPP are:

• Methotrexate
• Cyclosporine

If those don’t work or aren’t tolerated, the next ones to try may be:

• Enbrel (etanercept)
• Humira (adalimumab)
• Stelara (ustekinumab)
• Tremfya (guselkumab)

It’s also advisable to quit smoking and avoid contact irritants (allergens, harsh soaps).

Summary

Palmoplantar pustulosis is a rare skin condition that causes blisters to erupt on the palms and soles. This may lead to red, scaly areas with skin that cracks easily. Pustules may itch, burn, or be debilitatingly painful.

The causes of PPP aren’t known. Smoking, bacterial infections, skin allergies, and genetics may play a role. Diagnosis may involve an exam, swabs of pustule fluid, or in rare cases, a biopsy.

Treatment for PPP may consist of topical steroids, retinoids, moisturizers, phototherapy, and immunosuppressants.

A Word From Verywell

A skin condition that’s both painful and unsightly can take a toll on you mentally and physically. Don’t hesitate to reach out to your healthcare provider about PPP and about any negative thoughts or feelings you have toward it. You may benefit from talking to a mental health professional.

Frequently Asked Questions

Is palmoplantar pustulosis a type of psoriasis?

PPP may be a type of psoriasis. Some healthcare providers believe it is, while others consider it a separate condition. This disagreement may be settled by future research.

Does palmoplantar pustulosis go away?

Outbreaks of PPP will go away eventually, especially with treatment. PPP can’t be cured, though, so there’s never a guarantee that you won’t have another flare-up.

How rare is palmoplantar pustulosis?

PPP is quite rare. Between 0.01% and 0.05% of the population is estimated to have it.