A 53-year-old woman is referred by her podiatrist for evaluation and treatment of a rash affecting both feet that has been present for many years. Treatment with a variety of steroid creams had provided limited improvement, and ambulation is at times labored due to pain. The patient has a history of hypertension and adult onset diabetes. Upon physical examination, erythema of her palms and soles is observed accompanied by scaling, pustules, and hemorrhagic macules. No other cutaneous abnormalities were noted but the patient states that the rash also has appeared on her hands.
Submit your diagnosis to see full explanation.
Palmoplantar psoriasis (PPP) is a variant of psoriasis that affects the palms and soles.1 The condition commonly begins as an eruption of pin-sized, sterile, yellowish pustules and over time develops varying degrees of hyperkeratosis, erythema, scaling and fissuring. The thenar and hypothenar eminence and central portions of the palms and soles are frequently affected. Once resolved, pustules often manifest as hyperpigmented macules. The nails are involved in a majority of cases; findings may include pitting, subungual hyperkeratosis, and longitudinal ridging.2
Histologic findings of PPP include parakeratosis within the stratum corneum and hyperkeratosis within the stratum spinosum. This is accompanied by a decrease or loss of the epidermal granular layer and collection of neutrophils.3
PPP has been linked to both hereditary predisposition and environmental triggers, which include smoking, irritants, friction, and manual or repetitive trauma. A significant percentage of patients with PPP are smokers, and it has been postulated that activation of nicotine receptors in sweats glands contributes to the inflammatory disease process.1
Treatment for PPP usually begins with topical agents such as corticosteroids and calcipotriol; second-line therapies include acitretin, methotrexate, and ultraviolet light therapy.4 Resistant cases have improved with a wide spectrum of biologics including tumor necrosis factor-alpha inhibitors, phosphodiesterase type 4 inhibitors, and interleukin (IL)-17 and IL-23 inhibitors.4-6
Sara Mahmood, DPN, is a podiatry/dermatology fellow under the auspices of St. Lukes Hospital and DermDox Dermatology Centers. Stephen Schleicher, MD, is director of the DermDox Center for Dermatology in Pennsylvania, as well as an associate professor of medicine at Commonwealth Medical College and a clinical instructor of dermatology at Arcadia University and Kings College.
1. Engin B, Aşkın Ö, Tüzün Y. Palmoplantar psoriasis. Clin Dermatol. 2017;35(1):19-27. doi:10.1016/j.clindermatol.2016.09.004
2. Choi JW, Kim BR, Seo E, Youn SW. Identification of nail features associated with psoriasis severity. J Dermatol. 2017;44(2):147-153. doi:10.1111/1346-8138.13565
3. Rao A, Khandpur S, Kalaivani M. A study of the histopathology of palmo-plantar psoriasis and hyperkeratotic palmo-plantar dermatitis. Indian J Dermatol Venerol Leprol. 2018;84(1):27-33. doi:10.4103/ijdvl.IJDVL_71_16
4. Raposo I, Torres T. Palmoplantar psoriasis and palmoplantar pustulosis: current treatment and future prospects. Am J Clin Dermatol. 2016;17(4):349-358. doi:10.1007/s40257-016-0191-7
5. Falto-Aizpurua LA, Martin-Garcia RF, Carrasquillo OY, Nevares-Pomales OW, Sánchez-Flores X, Lorenzo-Rios D. Biological therapy for pustular psoriasis: a systematic review. Int J Dermatol. 2020;59(3):284-296. doi:10.1111/ijd.14671
6. Sanchez IM, Sorenson E, Levin E, Liao W. The efficacy of biologic therapy for the management of palmoplantar psoriasis and palmoplantar pustulosis: a systematic review. Dermatol Ther (Heidelb). 2017;7(4):425-446. doi:10.1007/s13555-017-0207-0