Generalized pustular psoriasis (GPP) is a rare, severe form of psoriasis characterized by sterile pustules across large areas of skin. The condition most commonly affects individuals between the ages of 40 and 59 years. GPP may occur alongside plaque psoriasis and other comorbidities.
GPP typically presents with systemic symptoms. Diagnostic testing includes laboratory studies evaluating elevated erythrocyte sedimentation rate, elevated C-reactive protein levels, absolute lymphopenia at onset quickly followed by polymorphonuclear leukocytosis, low plasma albumin, zinc, and calcium, and deranged lipid profile.
Treatment of GPP consists of symptom management strategies, topical medications, as well as systemic treatment options.
Epidemiology and Pathophysiology
GPP is considered a rare condition, with a prevalence of about 198 per million and an incidence of 27.2 per million person-years. Typically, onset occurs between the ages of 40 and 59 years, although rarer cases have been reported in infants and children. In some studies of the condition, women are observed to have higher incidence rates, although these results remain inconsistent. GPP is often associated with plaque psoriasis, inflammatory polyarthritis, obesity, hypertension, dyslipidemia, and diabetes.
In both familial and sporadic GPP, deleterious germline mutations in IL36RN have been reported. While the specific mutations in this gene vary from patient to patient, these mutations put patients at a higher risk of early-onset disease and systemic inflammatory response.
IL36RN encodes the IL-36 receptor antagonist that is expressed primarily in the skin. It is also the antagonist of three pro-inflammatory cytokines of the interleukin-1 family. IL-36 cytokines are overexpressed in patients with plaque psoriasis, signaling its role in cutaneous inflammation. However, this role is thought to be by a different mechanism in GPP.
Additionally, mostly in patients with GPP and coexistent plaque psoriasis, there are occasional reports of mutations in CARD14.
Signs and Symptoms
Common signs and symptoms of GPP include:
- Pustules across large areas of the skin
- Burning sensation or pain in the skin
- Fever
- Weakness and fatigue
Management and Current Treatment
Treatment of GPP includes symptom management to deal with issues such as fluid and protein intake, treating infections, preventing hypothermia, and terminating pregnancy in the case of risk of maternal life. Additionally, topical treatments such as bland emollients and diluted corticosteroids are used. First line systemic treatments options include acitretin 1 mg/kg/day, ciclosporin 3.5 to 5 mg/kg/day, and methotrexate 0.2 to 0.4 mg/kg/day.
Clinical Trial Information
For a list clinical trials regarding GPP, visit https://clinicaltrials.gov/search?cond=Generalized%20Pustular%20Psoriasis
Resources
International Psoriasis Council
References
Mirza HA, Badri T, Kwan E. Generalized Pustular Psoriasis. StatPearls Publishing LLC, 2022. https://www.ncbi.nlm.nih.gov/books/NBK493189/
Choon SE, et al. Incidence and prevalence of generalized pustular psoriasis in multiethnic Johor Bahru, Malaysia: a population-based cohort study using routinely captured electronic health records in the Teleprimary Care (TPC®) clinical information system from 2010 to 2020. Br J Dermatol. 2023 Sep 15;189(4):410-418. doi: 10.1093/bjd/ljad158. PMID: 37162007.
To learn more about rare skin conditions, visit https://checkrare.com/diseases/skin-conditions/