Effective Treatment of Prurigo Nodularis with Dupilumab: A Case Report

Sir,

Prurigo Nodularis (PN) is a chronic skin disease that is difficult to treat and always with severe pruritus. The lesions are usually symmetrically distributed on the extended sides of the extremities. Effective therapeutic options are limited, and long-term treatment with off-label systemic medications such as cyclosporine, methotrexate, or thalidomide may result in significant side effects. Dupilumab is a monoclonal antibody targeting the IL-4 and IL-13, which are the Th2 cytokines. Recent reports demonstrated that dupilumab may be a safe and efficient treatment in atopic and non-atopic PN. Here, we report a case of refractory PN, which was successfully treated by dupilumab.

A 51-year-old male came to our department presented with pruritic papules and nodules affecting his extremities and torso for over ten years [Figures 1 and 2]. Neither did he have a history of atopic diseases such as asthma, allergic rhinitis, or atopic dermatitis, nor did his first-degree relatives. He was treated with immunosuppressant, topical steroids, antihistamines and oral antibiotics without resolution before. According to his clinical manifestations and lesional histopathology, a diagnosis of PN was made. His serum total IgE was normal. The Dermatology Life Quality Index (DLQI) was 8, pruritus and sleep loss were 6/10 and 5/10 [Figure 1], respectively, on a numerical rating scale (NRS) (score 0–10). On treatment, the patient was first given Dupilumab 600 mg followed by 300 mg every 2 weeks subcutaneously, the total course of treatment being 16 weeks. After only 2 weeks (combined therapy of topical steroids with levocetirizine 5 mg per night), his itching was lessened. The NRS of pruritus and sleep loss, respectively, were only 2/10 and 1.5/10. Then, he stopped topical steroids and levocetirizine from the third week. After 16 weeks of treatment, the NRS of pruritus and sleep loss, respectively, were 0.5/10 and 0/10, resulting in a significant improvement in the quality of life, as evidenced by the DLQI score of 2 [Figure 1 and 2]. Obviously, with the notable reduction of pruritus, the lesions were also reduced. The hypertrophic plaques and nodules were flattened or disappeared, and some were left with pigmentation only [Figure 2].

Figure 1.

Changes in clinical symptoms and medication regimen. TS, topical steriods; L, levocetirizine; DLQI, Dermatology Life Quality Index; NRSi and NRSs, numerical rating scale of itching and sleep loss; w, weeks

Figure 2.

Papules and nodules on the turnk and extremities noted before dupilumab treatment (upper lane) and the lesions significantly improved after 4 months of dupilumab injection (lower lane)

The pathogenesis of PN is still not clear. Studies have shown that expression of the T-helper type 2 cytokines (IL-4 and IL-13) has been observed in PN biopsies, suggesting that these mediators are important in PN.[1] Dupilumab can block IL-4 and IL-13, which may be one of the reasons that it is effective in treating PN. According to our case and those previous reports,[2,3] we believe that it is necessary to conduct further research to evaluate the long-term safety and effectiveness of dupilumab in PN.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his names and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.

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Nil.

Conflicts of interest

There are no conflicts of interest.