What indicates effective treatment when using diphenhydramine 1% as a topical agent for allergic dermatosis?

Effective treatment with diphenhydramine 1% as a topical agent for allergic dermatosis is primarily indicated by the relief of urticaria. Diphenhydramine is an antihistamine that works by blocking the action of histamine, a chemical released during an allergic reaction that contributes to symptoms like itching and hives (urticaria).

When the treatment is successful, the histaminic effects that cause the skin manifestations of allergic reactions, such as swelling and itching, diminish significantly. Thus, the relief of urticaria demonstrates that the antihistamine action of diphenhydramine is effectively managing the allergic response and alleviating the associated symptoms.

The other parameters mentioned, such as reduction of redness, minimization of pain, or decrease in inflammation, are important in evaluating overall skin condition but do not directly relate to the specific mechanism of action of diphenhydramine in managing urticaria associated with allergic dermatosis. These factors may improve as a result of effective histamine blockade, but they are not the primary indicators of the drug's effectiveness for the specific condition being treated.