The sawfly genus Croesus Leach (Hymenoptera: Allantinae) in India

Toxic Side Effects of Targeted Therapies and Immunotherapies Affecting the Skin, Oral Mucosa, Hair, and Nails

Targeted therapies and immunotherapies are associated with a wide range of dermatologic adverse events (dAEs) resulting from common signaling pathways involved in malignant behavior and normal homeostatic functions of the epidermis and dermis. Dermatologic toxicities include damage to the skin, oral mucosa, hair, and nails. Acneiform rash is the most common dAE, observed in 25–85% of patients treated by epidermal growth factor receptor and mitogen-activated protein kinase kinase inhibitors. BRAF inhibitors mostly induce secondary skin tumors, squamous cell carcinoma and keratoacanthomas, changes in pre-existing pigmented lesions, as well as hand-foot skin reactions and maculopapular hypersensitivity-like rash. Immune checkpoint inhibitors (ICIs) most frequently induce nonspecific maculopapular rash, but also eczema-like or psoriatic lesions, lichenoid dermatitis, xerosis, and pruritus. Of the oral mucosal toxicities observed with targeted therapies, oral mucositis is the most frequent with mammalian target of rapamycin (mTOR) inhibitors, followed by stomatitis associated to multikinase angiogenesis and HER inhibitors, geographic tongue, oral hyperkeratotic lesions, lichenoid reactions, and hyperpigmentation. ICIs typically induce oral lichenoid reactions and xerostomia. Targeted therapies and endocrine therapy also commonly induce alopecia, although this is still underreported with the latter. Finally, targeted therapies may damage nail folds, with paronychia and periungual pyogenic granuloma distinct from chemotherapy-induced lesions. Mild onycholysis, brittle nails, and a slower nail growth rate may also be observed. Targeted therapies and immunotherapies often profoundly diminish patients’ quality of life, which impacts treatment outcomes. Close collaboration between dermatologists and oncologists is therefore essential.

Successful desensitization protocol for hypersensitivity reaction probably caused by dabrafenib in a patient with metastatic melanoma

Vemurafenib and dabrafenib are both orally bioavailable small molecule agents that block mitogen activated protein kinase signalling in patients with melanoma and BRAF(V600E) mutation. Generalized hypersensitivity reactions to vemurafenib or dabrafenib have not been described. Continuing vemurafenib or dabrafenib therapy despite hypersensitivity reaction is especially important in patients with melanoma and BRAF(V600E) mutation, in whom this mutation plays a critical role in tumour growth. Desensitization protocols to overcome hypersensitivity reactions by gradual reintroduction of small amounts of the offending drug up to full therapeutic doses are available for many anti-cancer agents, including vemurafenib but, to the best of our knowledge, have not been reported for dabrafenib. We describe a patient with metastatic melanoma who developed Type I hypersensitivity reaction to vemurafenib and to subsequent treatment with dabrafenib, and who was successfully treated by drug desensitization which allowed safe prolonged continuation of dabrafenib. The development of hypersensitivity reactions for both dabrafenib and vemurafinib in the current case could be because these drugs have a similar chemical structure and cause a cross-reactivity. However, hypersensitivity reaction to a non-medicinal ingredient shared by the two drugs is also possible. Oral desensitization appears to be an option for patients with hypersensitivity Type I to dabrafenib. This approach may permit clinicians to safely administer dabrafenib to patients who experience hypersensitivity reactions to this life-prolonging medication.