Table 2.

Reading criteria of the ICDRG, adapted from the study by Stingeni et al. (95).

Symbol	Morphology	Assessment
−	No reaction	Negative reaction
?+	Faint erythema only	Doubtful reaction
+	Erythema, infiltration, possibly papules	Weak positive reaction
++	Erythema, infiltration, papules, vescicles	Strong positive reaction
+++	Intense erythema, infiltrate, coalescing vescicles	Extreme positive reaction
IR	Various morphology, e.g., soap effect, bulla, necrosis	Irritant reaction