DISCUSSION

DEB is an autosomal dominant or recessive genodermatosis caused by variations in COL7A1. Its pathogenesis is not completely understood. EBP is characterized by nodular prurigo-like lichenoid lesions with intense itching, in addition to the features of DEB, such as blisters and onychodystrophy. 1 Currently, EBP is treated with topical corticosteroids, tacrolimus, and oral thalidomide, but the outcomes are often unsatisfactory.2-3 Baricitinib is a reversible selective inhibitor of tyrosine protein kinase, which is capable of modulating the signal transduction of helper T-cells (Th1, Th2, Th17, and Th22) and participates in many immune-mediated disorders. Here, one case of baricitinib in the treatment of EBP was discussed.
This case clinically presented with dense nodular, keratotic papules, mainly on the extensor side of both lower limbs, which were brownish in color, with umbilical concavity at the center of some of them, and subepidermal blisters could be seen by the results of the examination, while there were no obvious eosinophils in the blisters, and there was mixed inflammatory cell infiltration in the dermis, so we considered this to be a case of a specific type, Epidermolysis Bullosa Pruriginosa. Janus kinase-signal transducer and activator of transcription (JAK-STAT) is an intracellular signaling pathway upon which many different proinflammatory signaling pathways converge. Numerous inflammatory dermatoses are driven by soluble inflammatory mediators, which rely on JAK-STAT signaling, and inhibition of this pathway using JAK inhibitors might be a useful therapeutic strategy for these diseases. Evidence suggests that the dysregulation of helper T-cell (Th1, Th2, and Th17) signal transduction is implicated in epidermolysis bullosa. Chronic inflammation is a hallmark of DEB, thus upregulation of inflammatory cytokines and JAK signaling may play a role in DEB-related pruritus. Caroppo reported one case of EBP who was successfully treated with dupilumab. Dupilumab can dually block and inhibit both IL-4 and IL-13 and suppress Th2-mediated inflammatory responses, thus significantly improving skin lesions and relieving itching.4 This suggests that EBP may be triggered by Th2 immune mechanisms. In addition, it was reported that baricitinib could alleviate itching associated with AD, and the significant relief of itching proves the effectiveness of this strategy, which is the rationale behind the application of baricitinib in our hospital for targeted treatment through its downstream JAK-STAT signal. JAK may be a favored target for EBP-associated symptoms. Moreover, considering the affordability and durability of the treatment regimen for patients, baricitinib has become the preferred treatment choice in our clinic instead of dupilumab. Jiang XY et al. reported one case of EBP in a 40-year-old man without a family history of DEB and with severe skin lesions and intense itching, which is significantly improved after treatment with baricitinib. 5 He was followed up once every 2 weeks until 16 weeks, and then every 8 weeks. The scores of all three indicators decreased over time. Joo Kwon retrospectively reviewed the medical records of DEB patients with refractory pruritus who were treated with either baricitinib, a JAK1/2 inhibitor, or upadacitinib, a selective JAK1 inhibitor. A total of 12 DEB patients (six recessive DEB and six dominant DEB) were included in this study. The mean±SD baseline pruritus visual analog scale score was 7.5 ± 1.7. Upadacitinib or baricitinib treatment resulted in a rapid and sustained decrease in itch.6
In this paper, one case of EBP was discussed. The patient had a long history of EBP and a relevant family history of the disease. The typical skin lesions initially manifested as multiple lichenoid papules and nodules on both lower extremities, especially their extensor aspect, with scars forming in the center of the larger nodules, accompanied by mild scale. Combined with the fact that the results of previous examinations, the herpetic autoantibody test, and other examinations were all negative, prurigo nodularis and herpes could be excluded. The patient had intense itching, which is one of the important manifestations of EBP. The patient had received traditional treatment for more than 10 years, and while the progression of the disease had been controlled to a certain extent, the outcome of itching relief was unsatisfactory. The patient was treated with baricitinib in our hospital with the hope of relieving the itching. During the 2 years of treatment with baricitinib, the patient’s skin rashes had subsided and flattened significantly, and his itching was markedly relieved. The VAS itching score of the patient was assessed at follow-up, and the point plot showed that the score had gradually declined from 8–9 points to 2–3 points, indicating a greatly improved quality of life.
EBP is a persistent, recurring disease that seriously affects quality of life. this study confirms that baricitinib is effective and feasible in treating EBP, especially in significantly relieving itching, which rendered new ideas for therapeutic approaches for EBP in the future. Particularly important for patients suffering from severe itchiness.