Excimer light therapy with systemic corticosteroids improved severe chronic nodular prurigo and altered peripheral nerve fibers in the epidermis

Chronic nodular prurigo (CNPG) is a pruritic, chronic skin disease clinically defined by hyperkeratotic or erosive nodules [1‐3]. In this study, we focus on patients with severe CNPG on the extremities and trunk who present with itchy skin lesions. CNPG is resistant to a variety of treatments. Most patients with CNPG receive insufficient therapies such as topical anti-inflammatory treatment and H₁ antihistamines. However, some reports have shown that high-intensity excimer light (EL) therapy is effective for CNPG [4‐6]. EL therapy at a wavelength of 308 nm has a therapeutic effect with low cumulative UV dosage and a low risk of DNA damage because it requires a short irradiation time. It is safe and effective for the treatment of chronic skin diseases, including psoriasis, atopic dermatitis, and palmoplantar pustulosis [7‐9]. EL therapy is also an effective treatment for CNPG and related diseases because high-density light deeply penetrates the skin. We present two cases of severe CNPG treated successfully with EL therapy and oral prednisolone. …