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