Table 1.

Classification of Skin Toxicities Induced by Checkpoint Inhibitors

Category	Skin Disorder	Frequency
Skin rashes/inflammatory dermatitis	Maculopapular Lichenoid Psoriasiform Eczematous Neutrophilic dermatoses	Frequent Frequent Frequent Frequent Rare
Bullous eruptions	Bullous pemphigoid, bullous lichen, lichen pemphigoides, linear IgA bullous dermatosis, bullous drug eruption	Rare
Pruritus	Isolated or in association with skin rashes	Frequent
Pigmentary disorders	Vitiligo Regression of melanocytic nevi and other pigmented lesions	Frequent Less frequent (pigmentary disorders are mainly seen among melanoma patients while it is rare in other tumors)
Severe cutaneous adverse reactions/life-threatening drug reactions	Drug reaction with eosinophilia and systemic symptoms (DRESS)/drug-induced hypersensitivity syndrome (DIHS) Steven-Johnson syndrome (SJS) Toxic epidermal necrolysis (TEN) Acute generalized exanthematous pustulosis (AGEP)	Rare
Miscellaneous	Grover disease Vasculitis Dermatomyositis Sjögren syndrome Sarcoidosis Urticaria Acneiform/papulopustular rocasea Prurigo simplex/nodularis Nail, hair, oral mucosa	Rare Rare Rare Rare Less frequent Rare Rare Rare Less frequent