No. Marcin is an antibiotic used to treat bacterial infections. Allergic skin rashes caused by environmental factors (like pollen, dust, or chemicals) are not due to bacteria, but rather an immune/allergic reaction. In such cases, Marcin will not be effective. Allergic rashes are typically managed with antihistamines, antihistamine creams, or corticosteroids, depending on their severity. Always consult a doctor before starting any treatment.