Table 1.

Rash rating scales used in this investigation

Grade	EGFR-Inhibitor induced rash scale	CTCAE Assessment scale
0	No rash	No rash
1	Isolated pustule or erythematous patch < 1 cm in diameter, on either face/head/neck or chest/back	Macular or papular eruption or erythema without associated symptoms
2	More than one erythematous patch or erythema and telangiectasia on either face/head/neck or chest/back	Macular or papular eruption or erythema with pruritus or other associated symptoms; localized desquamation or other lesions covering < 50% of body surface area
3	More than one pustule or papules on either face/head/neck or chest/back with no associated erythema or telangiectasia	Severe, generalized erythroderma or macular, papular or vesicular eruption; desquamation covering ≥ 50% body surface area
4	Both erythema/telangiectasia and pustules/papules limited to either face/head/neck or chest/back	Generalized exfoliative, ulcerative, or bullous dermatitis
5	Pustules or papules and erythema/telangiectasia present on both the face/head/neck region and the chest/back	Death