What is palmoplantar pustulosis?
‘Palmoplantar’ literally refers to the palms of the hands and soles of the feet. One of the characteristics of palmoplantar pustulosis is the formation of ‘pustules’ (red area containing pus) on the palms of the hands and soles of the feet (figure 1). The pustule formation continuously takes place under the cycle that usually starts as tiny blisters on the aforementioned area which gradually becomes filled with pus inside and finally sheds. The affected skin usually shows reddish change (Photo 1). Both palms of the hands and soles of the feet can be involved; however, it can affect any combination of the palms or feet.
The condition can also cause the fingernails and/or toenails to be deformed.
Having these eruptions of palmoplantar pustulosis can accompany pain and/or itchiness and can negatively affect the patient’s quality of life.
In the rare cases, the midline joint between the right and left clavicles (sterno-clavicular joint) and some other joint inflammation may accompany the skin symptoms, the condition known as palmoplantar osteo-arthritis.
The condition can also cause the fingernails and/or toenails to be deformed.
Having these eruptions of palmoplantar pustulosis can accompany pain and/or itchiness and can negatively affect the patient’s quality of life.
In the rare cases, the midline joint between the right and left clavicles (sterno-clavicular joint) and some other joint inflammation may accompany the skin symptoms, the condition known as palmoplantar osteo-arthritis.
Figure 1. In palmoplantar pustulosis, patients show redness and pustule formation on the palms of the hands and soles of the feet.
Photo 1. Murakami M et al. J Invest Dermatol 2010; 130: 2010-6
The diagnosis of palmoplantar pustulosis
The diagnosis of palmplantar pustulosis can be made by a dermatologist upon seeing if the affected area shows typical tiny blisters and pustules on the palms of the hands and the soles of the feet, however it is occasionally difficult to differentiate from other dermatological conditions such as dyshidrotic eczema (a type of hand eczema).
In order to make a correct diagnosis, we may propose a skin biopsy (to cut out the blister or pustule under local anesthesia). We consider the correct diagnosis as very important since this can be a first step to appropriate treatment.
In order to make a correct diagnosis, we may propose a skin biopsy (to cut out the blister or pustule under local anesthesia). We consider the correct diagnosis as very important since this can be a first step to appropriate treatment.
How many patients are suffering?
The prevalence of palmoplantar pustulosis seems to vary by region of the world, race, and gender.
Statistically it is speculated that we have 1 to 2 patients with palmoplantar pustulosis among 1,000 people in Japan (1), meanwhile the rate is reported to be 1 to 2 out of 10,000 people in the US and the UK (2)(3). Thus, the prevalence seems to be disproportionately affecting Asian populations including Japan as compared with Europe and North America.
Female gender tends to have a higher prevalence than males according to many reports (Male to female ratio is almost 1 to 2 in Japan). Peak prevalence age is reported to be between 30’s and 50’s. Also, patients tend to seek medical attention in summer rather than in winter
(the patient usually experiences worsening of the symptoms in hotter seasons)(1).
(1）Kubota K et al. BMJ Open 2015: 5: e006450
(2) Frysz M,et al: Br J Dermatol. 2024;191:529-538
(3) Ramcharran D,et al: Adv Ther. 2023;40:5090-5101
Statistically it is speculated that we have 1 to 2 patients with palmoplantar pustulosis among 1,000 people in Japan (1), meanwhile the rate is reported to be 1 to 2 out of 10,000 people in the US and the UK (2)(3). Thus, the prevalence seems to be disproportionately affecting Asian populations including Japan as compared with Europe and North America.
Female gender tends to have a higher prevalence than males according to many reports (Male to female ratio is almost 1 to 2 in Japan). Peak prevalence age is reported to be between 30’s and 50’s. Also, patients tend to seek medical attention in summer rather than in winter
(the patient usually experiences worsening of the symptoms in hotter seasons)(1).
(1）Kubota K et al. BMJ Open 2015: 5: e006450
(2) Frysz M,et al: Br J Dermatol. 2024;191:529-538
(3) Ramcharran D,et al: Adv Ther. 2023;40:5090-5101
What causes palmoplantar pustulosis?
The exact cause of PPP is still inconclusive.
But many exacerbating factors have been reported to date. At the same time, according to several reports, getting rid of these exacerbating factors can result in the alleviation or even permanent disappearance of the symptoms.
Many times these exacerbating factors are correlated with cigarette smoking, odontogenic focal infection, and tonsillar focal infection.
But many exacerbating factors have been reported to date. At the same time, according to several reports, getting rid of these exacerbating factors can result in the alleviation or even permanent disappearance of the symptoms.
Many times these exacerbating factors are correlated with cigarette smoking, odontogenic focal infection, and tonsillar focal infection.
A) Smoking Cigarettes
The smoking rate of the patients with palmoplantar pustulosis is reported to be as high as 70% to 90% 4)-5). Of course, this does not necessarily mean that everyone that smokes always have risk to develop palmoplantar pustulosis. By the way, the smoking rate of habitual smokers in Japan is reported to be 14.8 % in 2024 6). Also, studies have shown that quitting cigarette smoking had reduced the number of pustules of the hands and feet 7).
4) Akiyama T et al. J Dermatol, 22: 930, 1995
5) Erikson MO et al. Br J Dermatol 138: 390, 1998
6) Ministry of Health, Labor and Welfare website: 2024, National health insurance, nutritional assessment resutls
7) Michaelsson G et al. J Am Acad Dermatol, 54: 737, 2006
4) Akiyama T et al. J Dermatol, 22: 930, 1995
5) Erikson MO et al. Br J Dermatol 138: 390, 1998
6) Ministry of Health, Labor and Welfare website: 2024, National health insurance, nutritional assessment resutls
7) Michaelsson G et al. J Am Acad Dermatol, 54: 737, 2006
B) Odontogenic Focal Infection
Odontogenic Focal Infection refers to an infection around the teeth including periodontal disease (also known as gum disease in which a space between a tooth and gum becomes wide enough to gradually make the tooth loose), or apical periodontitis (an infection at the tip of a tooth root). There is a study that reported the complication rate of odontogenic focal infection to be more than 80 % of those diagnosed palmoplantar pustulosis patients 8). Also, dental treatment for these focal infection is reported to be effective to alleviate the symptoms of palmoplantar pustulosis in 60 % to 80 % of patients.
8) Kouno M et al: J Dermatol 44: 695-698, 2017
8) Kouno M et al: J Dermatol 44: 695-698, 2017
Image 2. In periodontal disease, the gum or jaw bones that support the teeth are gradually worn down due to chronic bacterial infection.
Image 3. Apical periodontitis is a condition in which an inflammation lesion develops in the root region of a tooth.
C) Tonsillar Focal Infection
In palmoplantar pustulosis, the tonsils can be a causative organ that may lead to the development and exacerbation of the skin symptoms on the palms and soles. Recurrent inflammation of the tonsils can cause the worsening of the symptoms, but the tonsils themselves can be involved in the symptoms of palms and soles regardless of the presence of inflammation. Also, some relief to complete disappearance of the skin eruptions of the palms and soles after surgical removal of the tonsils have been reported 9).
9) Kouno M,et al:J Dermatol 44:695-698,2017
9) Kouno M,et al:J Dermatol 44:695-698,2017
Image 4. The red structures on both sides at the back of the mouth are the tonsils.
Treatment of palmoplantar pustulosis
As for the treatment of palmoplantar pustulosis, we need to;
try to find and remove exacerbating factors in collaboration with other specialists such as an ENT doctor, and/ or a dentist.
2) topical or systemic treatment such as oral or injectable medications at a dermatology clinic.
At our clinic, both exacerbating factors and appropriate medications are simultaneously sought out for the symptom improvement.
try to find and remove exacerbating factors in collaboration with other specialists such as an ENT doctor, and/ or a dentist.
2) topical or systemic treatment such as oral or injectable medications at a dermatology clinic.
At our clinic, both exacerbating factors and appropriate medications are simultaneously sought out for the symptom improvement.
Figure 5. Overview of the Treatment Approacches for Palmoplantar Pustulosis
Investigation of the exacerbating factors of palmoplantar pustulosis
Trying to find and to treat the worsening factors of palmoplantar pustulosis plays a pivotal role as part of treatment in our approach against the disease since this can not only improve the symptoms but even lead to a cure. However, dealing with associated medical challenges such as quitting smoking, seeking dental treatment and the consideration of tonsil removal along with the collaboration with other medical specialists. At our clinic we proceed with such investigations with local credible internal medicine, dental and ENT clinics.
Smoking Cessation Counseling
The smoking rate of the patients with palmoplantar pustulosis is high and it is expected that kicking the habit of smoking can lead to the amelioration of the symptoms. If you have palmoplantar pustulosis and a smoking habit, we explain the importance of smoking cessation. If you feel difficulty stopping smoking, we might propose a reference to an affiliated nearby internal medicine clinic that provides smoking cessation counseling.
Investigation of dental problems
Treating gum disease or tooth root infection can lessen the symptoms or even cure the palmoplantar pustulosis. As for dental treatment, we propose to refer the patients to affiliated nearby dentists that pursue active treatment against correlated dental conditions.
Investigating ear-nose-throat problems
Sinusitis (an inflammation of the bone cavity around the nose) can be an exacerbating factor of palmoplantar pustulosis. Additionally, dental problems in the upper jaw bone can extend upwards to cause sinusitis. To reach the diagnosis of these problems, CT scan sometimes can be useful. If these conditions are suspected, we may propose you go to affiliated specialized diagnostic imaging clinic to have an imaging study.
Treatment of palmoplantar pustulosis with medications
Medications used for the treatment of palmoplantar pustulosis are composed of:
① Topical medications (treatment with cream or ointment)
② Oral medications (treatment with tablets or capsules)
③ Injection therapy (treatment with injectable biological drugs given subcutaneously)
① Topical medications (treatment with cream or ointment)
② Oral medications (treatment with tablets or capsules)
③ Injection therapy (treatment with injectable biological drugs given subcutaneously)
Topical treatment (treatment with cream or ointment)
Topical medications effective for palmoplantar pustulosis include topical corticosteroids and topical activated vitamin D3. At our clinic, these medications are prescribed in combination or, depending on the patient’s condition, individually.
Oral medications (treatment with tablets or capsules)
Medications such as etretinate, ciclosporin, and apremilast can be used orally.
Tygason® (etretinate) takes effect by modulating abnormally potentiated hardening of skin cells in palmoplantar pustulosis.
Neoral® (ciclosporin), an immunosuppressant, subdues an overshoot of inflammation of palmoplantar pustulosis.
Otezula® (apremilast) is newly approved in 2025 in the treatment of palmoplantar pustulosis, an immunomodulator which takes effect by adjusting the levels of cytokines that worsen the palmoplantar symptoms.
Tygason® (etretinate) takes effect by modulating abnormally potentiated hardening of skin cells in palmoplantar pustulosis.
Neoral® (ciclosporin), an immunosuppressant, subdues an overshoot of inflammation of palmoplantar pustulosis.
Otezula® (apremilast) is newly approved in 2025 in the treatment of palmoplantar pustulosis, an immunomodulator which takes effect by adjusting the levels of cytokines that worsen the palmoplantar symptoms.
Injection therapy (treatment with injectable biological drugs)
Three injectable biological drugs are now used in the treatment of palmoplantar pustulosis. Biological drugs, also known as biologics or biological agents are pharmaceutical drugs made from living sources or its products. Their use is considered if neither investigation and treatment of worsening factors nor topical or oral conventional therapy were unable to elicit sufficient treatment outcome.
It has been reported that IL-17 and IL-23, a type of proteins called cytokines, with which cells can communicate with one another are involved in the pathogenesis of palmoplantar pustulosis. Approved biological agents are designed to block either one of these cytokines to exert the efficacy against palmoplantar pustulosis.
In Japan, when using biological drugs, regular check-ups including blood tests, and imaging studies, and affiliation with a general hospital that is also approved for the use of biological agents, or with a hospital with board-certified respiratory physicians to deal with side-effects are recommended.
Our clinic is an approved institute for biological drugs, and we are committed to complying with these guides in our medical services.
In the introduction of, and continuous use of biological drugs, regular chest x-rays or chest CT scans, and blood tests including viral hepatitis infection check are required. Chest x-rays or chest CT scans must be done at the affiliated hospitals.
Treatment with biological drugs can be rather costly, and `High -Cost Medical Expense Benefit’ may apply to cover part of your medical expense if you have health insurance coverage in Japan and meet certain conditions.
We are committed to offering correct information regarding the medical subsidy system here in Japan, and practicing safe medical services.
It has been reported that IL-17 and IL-23, a type of proteins called cytokines, with which cells can communicate with one another are involved in the pathogenesis of palmoplantar pustulosis. Approved biological agents are designed to block either one of these cytokines to exert the efficacy against palmoplantar pustulosis.
In Japan, when using biological drugs, regular check-ups including blood tests, and imaging studies, and affiliation with a general hospital that is also approved for the use of biological agents, or with a hospital with board-certified respiratory physicians to deal with side-effects are recommended.
Our clinic is an approved institute for biological drugs, and we are committed to complying with these guides in our medical services.
In the introduction of, and continuous use of biological drugs, regular chest x-rays or chest CT scans, and blood tests including viral hepatitis infection check are required. Chest x-rays or chest CT scans must be done at the affiliated hospitals.
Treatment with biological drugs can be rather costly, and `High -Cost Medical Expense Benefit’ may apply to cover part of your medical expense if you have health insurance coverage in Japan and meet certain conditions.
We are committed to offering correct information regarding the medical subsidy system here in Japan, and practicing safe medical services.
Table 1. A list of biological drugs used in the treatment of palmoplantar pustulosis
These three biological drugs are used in the treatment of palmoplantar pustulosis as of 2026 in Japan. Target molecules for each biological drug is shown in red. LUMISEF ® is self-injectable (the patient injects on his or her own), but TREMFYA® and SKYRIZI® are not self-injectable and the healthcare provider will give an injection at the clinic.
|
Brand name (Generic name)
|
Target molecules (more specific target molecules)
|
Injection interval*
|
Self-injection
|
|
TREMFYA (Guselkumab)
|
IL-23 (IL-23p19)
|
8* weeks
|
×
|
|
SKYRIZI (Risankizumab)
|
IL-23 (IL-23p19)
|
12* weeks
|
×
|
|
LUMICEF (Brodalumab)
|
IL-17 (IL-17RA)
|
2* weeks
|
〇
|
*In the initial treatment phase of biological drugs, many have what we call a ‘loading schedule’, where the injection is given at intervals shorter than those listed in the table, in order to increase the blood concentration of the drug. The injection interval listed in the table is the injection intervals after the ‘loading schedule’.