Update on Diagnosis, Treatment Options for Palmoplantar Pustulosis

An overview of the current methods involved in diagnosis, screening, and treatment of palmoplantar pustulosis (PPP) was provided in a review published in Clinical, Cosmetic and Investigational Dermatology.

The disease, which may manifest as sterile, erupting pustules located on the soles of the feet and palms of the hands also presents with nail changes in more than 40% of patients. Irritant contact dermatitis, dyshidrotic eczema, pityriasis rubra pilaris, pompholyx, fungal infections, and acrodermatitis comprise the differential diagnosis of PPP. Triggering factors of PPP include smoking, infections (eg, tonsillitis and chronic sinusitis), psychological stress, allergies, and some drugs (eg, beta-blockers, antidiabetic therapies, and TNF inhibitors).

The standard treatment approach to PPP, although challenging, typically involves the use of topical and systemic therapies in addition to phototherapy and targeted molecules. There exists no “gold standard” in terms of therapy, and no available treatment is considered curative for the disease. Currently, control of mild PPP may be achieved with the use of on-demand occlusion of topical therapies. Arguably the best treatment option in this sense is oral acitretin, a vitamin A derivative, in combination with psoralen–ultraviolet A (PUVA).

Patients with refractory disease or patients with contraindications to acitretin and PUVA may be considered for biologic therapy or apremilast. Since levels of interleukin-17A (IL-17A) are often increased in PPP lesions, anti-IL-17A may be useful for patients with refractory PPP or those with contraindications to acitretin or PUVA. Anti-IL-23 agents may also prove effective for some patients with PPP.

Recent trials of PPP have centered on therapies that block IL-36 or IL-1β pathways, both of which are involved in innate immunity. Likewise, research has indicated that IL-36 isoforms are involved in psoriasis pathogenesis. Based on this research, blocking the IL-36 pathway has become an intriguing novel treatment target for PPP. A total of 3 studies are examining ANB019 and spesolimab – monoclonal antibodies that block the IL-36 receptor – in the disease.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Freitas E, Rodrigues MA, Torres T. Diagnosis, screening and treatment of patients with palmoplantar pustulosis (PPP): A review of current practices and recommendations. Clin Cosmet Investig Dermatol. 2020:13;561–578. doi:10.2147/CCID.S240607