Cellular evaluation of hypersensitivity to 2,4-dinitrochlorobenzene.

A suitable modification of the "skin window" method makes it possible to evaluate hypersensitivity reaction to 2,4-dinitrochlorobenzene at cellular level. Probands are sensitized by epicutaneous application of 0.2 ml of 1% solution of the tested substance, and after 14 days 1 drop of this solution is applied in the same manner on a freshly scraped area of the "skin window". An imprint preparation is taken 48 hours later and examined microscopically. Presence of lymphoid elements, eosinophils and basophils points to a normally developed hypersensitivity reaction. Presence at the same time of rather great amounts of large monocytogenic macrophages and neutrophilic granulocytes is an expression of an unspecific inflammatory reaction taking a normal course. Suitability of the described procedure for routine application is discussed.