OBJECTIVES

The severity and chronicity of itch of the dermatological condition prurigo nodularis (PN) drastically impacts quality of life (QoL) and there is no currently approved, effective treatment. Also, the prevalence of PN is unknown. Therefore, to assess the potential unmet medical need, we aim to estimate the prevalence and summarise the impact of PN on QoL.

METHODS

Prevalence of PN was estimated using German health insurance data (Benchmark). Patients with a new diagnosis of PN in 2012 were identified; incidence was converted to prevalence by applying the estimated duration of disease. To examine the impact of PN, a broad literature search was performed including 730 articles mentioning “prurigo” and “chronic/nodular/nodularis”.

RESULTS

In 2012, the Benchmark database provided 186 new diagnoses of PN out of 2.7 million enrolees giving an incidence of 0.68/10,000 person-years. Median age at diagnosis was 59 years. Thus, assuming a life-expectancy of 24 years as disease duration, we estimated a prevalence of 16.4/10,000. Four observational studies and one clinical trial (CT) provided suitable quantification of severity or QoL. The Numerical Rating Scale (NRS) in these PN patients (0: no itch; 10: worst itch) ranged from 7.8 to 8.7 and the CT reported baseline VAS of 8. A recent study of PN (Brenaut) reported an EQ-VAS of 57.4 and was the third worst skin disease in terms of QoL and showed a DLQI (dermatologic life quality index) of 12.4 and a suicide ideation rate of 19%.

CONCLUSIONS

An NRS of 8 implies “disabling, unable to perform activities of daily living” and the reported DLQI corresponds to a “very large” impact on QoL. These quantify the narrative of experts that PN “dramatically impairs patients’ quality of life” and is a “heavy burden” which may affect 16/10,000 people. Given the impact on patient life, there is an unmet need for effective treatment.