Efficacy of anti‐immunoglobulin E therapy in patients with prurigo: A pilot study

Abstract

Objectives Chronic prurigo is a reactive skin disease marked by multiple pruriginous lesions such as papules, nodules, and erythema. We previously showed that basophil infiltration into the pruriginous lesions and basophil activation in blood are frequently observed. Therefore, basophils may be involved in the pathogenesis of chronic prurigo. In this study, we examined the efficacy of anti‐immunoglobulin E (IgE) therapy with omalizumab, which blocks basophil activation, in patients with prurigo. Methods Seven patients with chronic prurigo (prurigo chronica multiformis [PCM]: five patients; prurigo nodularis [PN]: two patients) and one patient with prurigo subacuta (PS) were enrolled. The infiltration of basophils into skin lesions was assessed by immunohistochemical analyses using a monoclonal antibody. All patients were treated three times with 300 mg omalizumab every 4 weeks, regardless of serum levels of total IgE. Skin symptoms were assessed using our unique skin scores before and after treatment with omalizumab. The efficacy of the treatment was determined according to the reduction ratio of skin scores as follows: high (ratio > 70%), moderate (70% ≥ ratio > 40%), mild (40% ≥ ratio > 10%), or none (10% ≥ ratio). Results All five patients with PCM were improved: The efficacy was high for three patients, moderate for one patient, and mild for one patient. In addition, the pruriginous lesions were improved mildly in the patient with PS, but not in those with PN. Conclusions Anti‐IgE antibody therapy with omalizumab may be effective for PCM but not for the other types of chronic prurigo.

Chronic prurigo: A retrospective study of 168 cases

“…Analysis of treatment outcomes revealed that the efficacy of traditional therapy, such as topical steroids and UV radiotherapy, was not different in individuals with PN and PCM. In contrast, a previous clinical trial involving the treatment of chronic prurigo with omalizumab, which blocks basophil and mast cell function, reported that this compound successfully treated some patients with PCM and ameliorated eosinophilia (our preliminary data). Omalizumab was not, however, successful for other types of prurigo.…”

“…basophil and mast cell function, reported that this compound successfully treated some patients 7,8 with PCM and ameliorated eosinophilia (our preliminary data). Omalizumab was not, however, successful for other types of prurigo.…”

“…Overall, these data indicate that both PN and PCM show Th2‐predominant inflammation, although their underlying pathologies may be different. Based on our findings in this study, together with recent clinical data from the omalizumab trial, we discuss the evidence for distinct pathological mechanisms in the development of PN and PCM.…”

“…Basophil activation status in peripheral blood, as determined by cell surface CD203c expression levels, was also found to be higher in patients with chronic prurigo than in healthy donors . Recently, we encountered some patients who were successfully treated by the administration of omalizumab, a humanized anti‐immunoglobulin (Ig)E antibody . However, the different pathological mechanisms underlying the development of PN and PCM remain unclear.…”

“…5 Recently, we encountered some patients who were successfully treated by the administration of omalizumab, a humanized anti-immunoglobulin (Ig)E antibody. 7,8 However, the different pathological mechanisms underlying the development of PN and PCM remain unclear.…”