Background: Prurigo nodularis (PN) is a pruritic skin disease characterized by multiple intensely itchy skin nodules in symmetrically distributed areas of the extremities. There are limited studies on the epidemiology and treatment pathways of PN, especially moderate-to-severe PN, from England.
Objectives: To assess the epidemiology and treatment pathways of mild and moderate-to-severe PN in England.
Methods: This retrospective cohort study used data from the Clinical Practice Research Datalink and Hospital Episode Statistics in England. Adult patients (aged ≥ 18 years) with a PN-specific diagnosis code allocated any time between 1 April 2007 and 1 March 2019 (patient identification period) were selected. Patients were included if their first PN diagnostic code (index diagnosis date; IDD) was recorded during the identification period, with data available 6 months before and ≥ 12 months after the IDD. Patients were classified as having moderate-to-severe PN (MSPN) or mild PN (MiPN), based on the presence or absence of a prescription record, post-IDD, for either a systemic immunosuppressant or a gabapentinoid. Patients with MSPN and MiPN were matched 1 : 1 according to age, sex and IDD. Prevalence and incidence were calculated for each year from 2007 to 2019. Drugs prescribed post-IDD were analysed.
Results: A total of 8933 patients (MSPN, n = 2498; MiPN, n = 6435) were included in the study; 2462 patients with MiPN and 2462 with MSPN were included for the comparative analysis. The presence of atopic dermatitis, asthma and eosinophilic oesophagitis were significantly higher (all P < 0.001) in patients with MSPN compared with those with MiPN. The overall prevalence of cases of PN increased during the study period. The incidence rate also showed a similar trend. The rates of prescription of potent and super-potent topical corticosteroids (TCS), topical calcineurin inhibitors, first- and second-generation antihistamines, oral and injectable systemic corticosteroids, methotrexate, antidepressants and tacrolimus were significantly higher (all P < 0.001) in patients with MSPN compared with those with MiPN.
Conclusions: The epidemiology of PN was consistent with that found in other European studies. Patients with MSPN received a significantly higher number of prescriptions for potent TCS and systemic drugs compared with patients with MiPN.
Prurigo nodularis is an itchy skin disease that can affect a person’s daily life and sleep, and is often accompanied by other diseases. Skin ointments are used to treat the disease. If these are not effective, the disease is treated with oral medicine. The severity of prurigo nodularis is not well established. People with prurigo nodularis and treated with skin ointments are generally considered to have a milder form of the disease. Patients with severe disease most often require oral medicine that target the immune system. In England, there are no estimates of how often prurigo nodularis has affected the population over the last 10 years. In this study, we looked at cases of mild and moderate-to-severe prurigo nodularis in England and the treatments used by patients. We found that cases of prurigo nodularis (both mild and moderate-to-severe) increased during the study period, which was 2007 to 2019. Patients with the more severe form of the disease were more often treated with drugs that were not approved for treating it. Overall, our findings suggest that the number of patients with prurigo nodularis is increasing in England. A new and approved treatment option might be required to manage moderate-to-severe disease.
© The Author(s) 2024. Published by Oxford University Press on behalf of British Association of Dermatologists.