Pustular psoriasis refers to a heterogeneous group of chronic inflammatory skin disorders that are clinically, histologically, and genetically distinct from plaque psoriasis. Pustular psoriasis may present as a recurrent systemic illness (generalized pustular psoriasis [GPP]), or as localized disease affecting the palms and/or soles (palmoplantar pustulosis [PPP], also known as palmoplantar pustular psoriasis), or the digits/nail beds (acrodermatitis continua of Hallopeau [ACH]). These conditions are rare, but their possible severity and consequences should not be underestimated. GPP, especially an acute episode (flare), may be a medical emergency, with potentially life-threatening complications. PPP and ACH are often debilitating conditions. PPP is associated with impaired health-related quality of life and psychiatric morbidity, while ACH threatens irreversible nail and/or bone damage. These conditions can be difficult to diagnose; thus, primary care providers should not hesitate to contact a dermatologist for advice and/or patient referral. The role of corticosteroids in triggering and leading to flares of GPP should also be noted, and physicians should avoid the use of systemic corticosteroids in the management of any form of psoriasis.
Keywords: Acrodermatitis continua of Hallopeau; generalized pustular psoriasis; palmoplantar pustulosis; primary care; psoriasis; von Zumbusch.
PLAIN LANGUAGE SUMMARYA brief guide to pustular psoriasis for primary care providersPustular psoriasis consists of a group of rare conditions that cause the skin to become red and painful. In these conditions, small blisters filled with pus (called pustules) appear suddenly. The pustules are not infectious. Pustular psoriasis is different from plaque psoriasis, in which people develop scaly patches of skin. People can have pustular psoriasis and plaque psoriasis at the same time. Pustular psoriasis can be widespread, affecting large areas of the body, arms, and legs. This is called generalized pustular psoriasis (GPP). GPP can cause life-threatening complications that may require emergency medical treatment. Pustular psoriasis can be more localized, occurring on the palms of the hands and soles of the feet. This is called palmoplantar pustulosis (PPP). It can also occur on the fingers, toes, and nail beds, called acrodermatitis continua of Hallopeau (ACH). PPP and ACH can make walking and other everyday activities difficult. Because GPP, PPP, and ACH are rare, primary care providers are unlikely to meet many people with pustular psoriasis, so they may not recognize these conditions immediately. This article aims to help primary care providers assess and diagnose people who may have GPP, PPP, or ACH, and advise when they should get help from a skin specialist (dermatologist). See Figure 1 for a full infographic version of this summary.