Palmoplantar pustulosis

Management Strategy

PPP is often refractory to treatment and shows a high recurrence rate. Unlike psoriasis, there are no reported associations with candidate genes within the PSORS1 locus, interleukin-36 receptor antagonist mutations, or tumor necrosis factor (TNF)-α promoter polymorphisms. It predominantly affects middle-aged women and has a higher prevalence in smokers. No single factor appears to cause PPP although streptococcal or Helicobacter pylori infection, diabetes mellitus, thyroid disease, celiac disease, inflammatory arthritis, and metal allergy have all been implicated. Cessation of smoking is important for the treatment course of PPP. Tonsillectomy can be helpful if a streptococcal focus and association are found. A gluten-free diet is recommended if gluten intolerance is proved.

In the remainder of this chapter, we will review in depth the treatment options available for palmoplantar pustulosis. The allocation of each into first-, second- and third-line therapy is based on quality of study, efficacy, and treatment cost. In patients with milder symptoms of PPP, potent topical corticosteroids are the treatment of choice and are even more effective when used under occlusion. Studies on the vitamin D analog maxacalcitol show benefit compared with placebo for the topical treatment of PPP. Psoralen and ultraviolet A light (PUVA) therapy is also effective. Narrowband and broadband ultraviolet B (UVB) should not be considered. The retinoid acitretin (starting dose 0.3–0.5 mg/kg body weight) is of proven value, but its practical use in women and children is limited due to teratogenicity and premature closure of the epiphyseal growth plates. There is evidence that the combination of PUVA with systemic retinoids is superior to the individual treatments. Low-dose ciclosporin (1–4 mg/kg daily) and methotrexate (10–25 mg once weekly) can cause improvement of PPP but require careful clinical and laboratory monitoring. The oral phosphodiesterase-4 inhibitor apremilast showed mild to moderate improvement of disease.

Reports on TNF-α antagonist therapy in PPP show conflicting results, with many reports highlighting even induction or aggravation of the disease. Non-TNF-α–inhibiting biologic agents provide new therapeutic options, especially in recalcitrant cases. Controlled clinical trials on secukinumab (anti-IL–17A antibody), ustekinumab (anti-IL–12/23 p40 antibody), and guselkumab (IL-23 antibody) have shown efficacy in PPP. The effectiveness of other biologic therapies, such as brodalumab, an anti-IL–17RA antibody, as well as the oral Janus kinase inhibitor, is still unclear. More controlled clinical trials are needed to substantiate the evidence.