Skin reflectance measurements of patch test responses

Skin reflectance values were used as an objective measure of skin haemoglobin content at patch test sites to facilitate quantification of the erythematous response to contact allergens in patients with allergic contact dermatitis. Reflectance measurements of patch test responses correlated well with the clinical scoring and provided a numerical measure of reaction severity. Experimental contact allergen formulations were also evaluated by this method.