Non-inferiority Clinical Trial of Dexchlorpheniramine (Cream Versus Lotion) in the Relief of Insect Bite Related Symptoms

Insect bite related symptoms (pruritus and papules) are caused by the release of histamine by mast cells in the skin. Topical anti-histaminics can be used to promote relief of these symptoms. Dexchlorpheniramine maleate 1% cream is a topical anti-histaminic formulation approved by ANVISA in Brazil for the relief of skin irritation and allergies, including the ones caused by insect bites. The aim of the present study is to demonstrate non-inferiority of a new pharmacological preparation of dexchlorpheniramine maleate (1% lotion) with the standard preparation (1% cream) for the relief of insect bite related symptoms and to demonstrate the safety of both preparations.

• Drug: Dexchlorpheniramine 1% lotion
  Small amount applied over the lesion twice a day for 7 days.
• Drug: Dexchlorpheniramine 1% cream
  Small amount applied over the lesion twice a day for 7 days.

• Experimental: Dexchlorpheniramine 1% lotion
  Intervention: Drug: Dexchlorpheniramine 1% lotion
• Active Comparator: Dexchlorpheniramine 1% cream
  Intervention: Drug: Dexchlorpheniramine 1% cream

Inclusion Criteria:

• Presence of papules resulting from insect bites within the last 72 hours
• Presence of symmetric lesions to compare one side to the other
• Compliance of the subject to the treatment protocol
• Agreement with the terms of the informed consent by the participants or their legal guardians when younger than 18 years old

Exclusion Criteria:

• Pregnancy or risk of pregnancy
• Lactation
• Use of topical or systemic anti-inflammatory, anti-histaminics or immunosuppressive drugs within the last 48 hours prior to the study
• History of atopy or allergic diseases
• History of allergy of any component of the formulations
• Other conditions considered by the investigator as reasonable for non-eligibility