Management of Dermatitis Induced by Pembrolizumab

Introduction to Treatment Guidelines

The American Society of Clinical Oncology recommends topical corticosteroids as the first-line treatment for mild to moderate dermatitis caused by pembrolizumab, while oral corticosteroids should be used for severe or extensive dermatitis 1, 2

Evaluate the severity of dermatitis using CTCAE criteria, which categorizes it into Grade 1 (<10% body surface area), Grade 2 (10-30% BSA), Grade 3 (>30% BSA), or Grade 4 (life-threatening reactions) 2
Rule out other causes of skin reactions, including infections or effects from other medications, to ensure accurate diagnosis and treatment 2
Check for mucosal involvement and systemic symptoms to exclude dermatological emergencies like DRESS syndrome or SJS/TEN 2

For Grade 1 (Mild) dermatitis, continue pembrolizumab therapy and apply high-potency topical corticosteroids to affected areas, with the option to use emollients and antihistamines for symptom management 1, 2
For Grade 2 (Moderate) dermatitis, consider temporarily holding pembrolizumab therapy, apply high-potency topical corticosteroids, and start oral prednisone if necessary, with a steroid taper once improved 1, 2
For Grade 3 (Severe) dermatitis, hold pembrolizumab therapy, start oral prednisone, and consider dermatology consultation, with a steroid taper once improved 1, 2
For Grade 4 (Life-threatening) dermatitis, permanently discontinue pembrolizumab, hospitalize the patient, and administer high-dose systemic corticosteroids, with supportive care as needed 1, 2

Skin toxicities typically develop within days to weeks of starting treatment but can appear after several months, emphasizing the need for ongoing monitoring 1
Most dermatologic immune-related adverse events are low-grade and manageable, but severe events can occur more commonly with combination immunotherapy than with monotherapy 1, 2
Vitiligo is frequently seen in melanoma patients on checkpoint inhibitors and may be associated with a good clinical response, highlighting the complex relationship between treatment and immune response 2

Avoid using harsh soaps or cleansers containing alcohol, as they can worsen irritation, and instead use gentle skin care practices 2
Do not delay treatment of severe reactions, as they can rapidly progress to life-threatening conditions, emphasizing the importance of prompt intervention 1, 2
Do not permanently discontinue immunotherapy for mild to moderate dermatitis that responds to treatment, as this can impact overall patient outcomes 1