Palmoplantar pustulosis
Palmoplantar pustulosis is a rare skin condition characterized by the eruption of superficial pustules that primarily appear in palms and soles.
What is palmoplantar pustulosis?
Palmoplantar pustulosis, also called pustulosis palmaris et plantaris (PPP), is a rare non-contagious, chronic and inflammatory skin condition with an estimated prevalence of 0.050% to 0.12%. It is a localized form of pustular psoriasis, and is characterized by the appearance of painful sterile pustules -small skin lesions that contain pus- primarily in the palms of the hands and soles of the feet that erupt repeatedly over time. These pustules appear in conjunction with lesions that tend to crack, causing bleeding and pain.
In some cases, palmoplantar pustulosis also affects fingers and toes and causes nail lesions, and in severe cases some lesions may gradually enlarge and create patches that cover all the affected area. Affected individuals may also experience itching (pruritus), pain, or a burning sensation.
Signs and symptoms of palmoplantar pustulosis generally develop during adulthood (with the highest prevalence occurring between the ages of 50 and 69 years), and the condition is more common in women.
Though the area of involvement is often limited, PPP can have a significant impact on quality of life and can interfere with patients’ daily activities, such as walking, working or sleeping. Currently, there are experts who believe that this condition is related to psoriasis, since 10 to 25% of palmoplantar pustulosis patients also suffer from psoriasis, but the basis of these diseases is different.
What causes palmoplantar pustulosis?
The cause of palmoplantar pustulosis is currently unknown, but it is hypothesized to be a disorder of the eccrine sweat glands, which are most numerous on palms and soles, and that a combination of genetics (in concrete, a mutation in the gene IL36RN appearing in around 5% of PPP patients), autoinflammatory, and environmental factors likely play a role in its development. In this regard, this disease is strongly associated with smoking: majority of patients smoke or have smoked in the past (with an estimated (65–90%). It is thought that activated nicotine receptors in the sweat glands cause an inflammatory process.
How to detect palmoplantar pustulosis?
The appearance of pustules in the palms of the hands and soles of the feet is usually the most prevalent symptom of palmoplantar pustulosis. Diagnosis is usually easily made by healthcare providers through visual examination. A skin biopsy (a procedure in which skin cells are removed for their examination) might be useful to discard other health conditions.
How to prevent palmoplantar pustulosis?
Currently, there is not a described way to prevent palmoplantar pustulosis, but measures such as avoiding smoking, wearing comfortable footwear made from natural fibers or protecting your hands with gloves while doing manual labor, as well as getting treatment from the early stage of the condition can help to reduce flare-ups and prevent the disease progression.
How to treat palmoplantar pustulosis?
There is no cure for palmoplantar pustulosis, and its treatment is challenging, as currently there is not any approved treatment specifically for this disease in the US or the EU. However, there are several treatments that can help alleviate its symptoms. Some of the most common ones are:
- Topical corticosteroids: The use of creams and ointments with topical steroids, which are anti-inflammatory agents, can be useful to treat the disease. However, these treatments must be used during limited periods of time due to side effects and efficacy loss.
- Phototherapy: Ultraviolet B phototherapy and photochemotherapy can be very effective at managing the symptoms.
- Oral retinoids: This kind of drug, commonly used for treating psoriasis, can be helpful to control the disease in severe cases.
- Coal tar ointments: When applied directly to pustules, these ointments can be useful to prevent reappearance.
- Skin-moisturizing creams and ointments: Softening dry skin is important to prevent skin fissures.
References
- DermNet. Palmoplantar pustulosis. Available at: Palmoplantar pustulosis (localised pustular psoriasis) | DermNet (dermnetnz.org)
- Orphanet. Pustulosis palmaris et plantaris. Available at: Orphanet: Pustulosis palmaris et plantaris
- Genetic and Rare Diseases Information Center. Pustulosis palmaris et plantaris. Available at: Pustulosis palmaris et plantaris - About the Disease - Genetic and Rare Diseases Information Center (nih.gov)
- Brunasso AMG and Massone C. Recent advances in palmoplantar pustulosis. Faculty Reviews. 2021;10:(62) https://doi. org/10.12703/r/10-62
- Kromer C. et al. Drug survival and reasons for drug discontinuation in palmoplantar pustulosis: a retrospective multicenter study. J Dtsch Dermatol Ges. 2019 May;17(5):503-516. doi: 10.1111/ddg.13834. Epub 2019 Apr 17. PMID: 30994260; PMCID: PMC6850581.
- Genovese G. et al. Pustular Psoriasis: From Pathophysiology to Treatment. Biomedicines. 2021 Nov 23;9(12):1746. doi: 10.3390/biomedicines9121746. PMID: 34944562; PMCID: PMC8698272.