ACKNOWLEDGMENTS

I would like to thank Dr. Rui Zheng for her kind guidance on this paper.

Figure 1 Hyperkeratosis, epidermal hyperplasia, and fissures can be seen at the junction of the true epidermis, inflammatory cells, mainly lymphocytes, were seen around the vessels in the superficial dermis (A, scale bar: 50μm). Epidermis showed subepidermal bulla. Dermis shows mixed inflammatory infiltrate (B, HE×40). multiple reddish-brown hemispherical mung bean-to-soybean-sized nodules were symmetrically distributed on the bilateral calves and right thigh, densely packed in patches, some of which were anabrotic and crustosus due to the intense itching (C and D). After 2 years of baricitinib treatment, the results uncovered that the number of skin rashes on the outer side of both thighs had decreased by half, and the color had become dull, although some dark brown hyperpigmentation and scars remained on the extensor aspect of both lower legs (E and F).

Figure 2 Change in VAS after oral baricitinib treatment showed a gradual downward trend, Patient’s past and current treatment plan.