Oral sirolimus for the treatment of juvenile xanthogranuloma: Report of two pediatric cases.

Juvenile xanthogranuloma (JXG) with extensive cutaneous or visceral organ involvement is often associated with high morbidity and treatment commonly involves surgical excision, radiotherapy, systemic steroids, or chemotherapy. Sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, is an oral antitumor and immunosuppressive therapy used to treat various neoplastic disorders, including histiocytic disorders. We report two pediatric cases of JXG successfully treated with oral sirolimus monotherapy, and postulate that sirolimus may induce rapid disease resolution and long-term remission for patients with both skin-limited and multisystemic JXG. Our findings warrant further investigation of the relationship between the mTOR pathway and JXG.

Improvement of Recalcitrant Dissecting Cellulitis of the Scalp After a Trial of Upadacitinib.

Dissecting cellulitis of the scalp (DCS) is a rare condition characterized by painful inflammatory nodules and abscesses on the scalp, often leading to sinus tracts and scarring alopecia. We present a case of DCS in a 26-year-old male who experienced significant clinical improvement following a short course of upadacitinib, a Janus kinase (JAK) inhibitor. The patient received multiple standard treatments such as topical antimicrobials, oral antibiotics, corticosteroids, and intralesional triamcinolone injections, with limited success. However, following the initiation of upadacitinib, the patient reported reduced pain, pustular draining, and bleeding, with significantly improved quality of life. To our knowledge, there is currently a paucity of literature documenting the use of JAK inhibitors for DCS. This case aims to highlight the potential of JAK inhibitors as a therapy for refractory DCS, a condition with limited treatment options.

Skin reactions to tyrosine kinase inhibitors in pediatric patients with chronic myeloid leukemia.

Cutaneous adverse events are commonly reported in adult patients with chronic myeloid leukemia (CML) receiving tyrosine kinase inhibitors (TKIs); however, little is known about the cutaneous reactions in children receiving TKIs for CML. As pediatric patients may require lifelong TKI therapy, it is essential to understand the wide range of potential cutaneous toxicities. We examined all case studies, cohort studies, and clinical trials in PubMed/MEDLINE and Embase that reported cutaneous reactions to first-, second-, and third-generation TKIs in children 18 years or younger with CML. This review article focuses on the TKI drug types and doses, patient demographic characteristics, features of skin reactions, and clinical outcomes.