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 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.

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

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.

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.

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.

掌蹠膿疱症の薬剤による治療は、外用療法(塗り薬による治療)、内服療法(飲み薬による治療)、注射薬による治療(生物学的製剤による治療)があります。