Final answer:
Mild allergic reactions have mild adverse effects such as sneezing and itchy eyes. Antihistamines can treat these symptoms, but caution should be taken with interactions and contraindications.
Step-by-step explanation:
Mild allergic reactions typically have mild adverse effects such as sneezing, itchy or watery eyes, and a runny nose. These symptoms can be treated with antihistamines which reduce or eliminate the effects of the histamines released during an allergic reaction. Interactions with other medications can occur, so it's important to consult with a healthcare professional before taking antihistamines along with other drugs. As for contraindications, antihistamines may not be suitable for individuals with certain medical conditions such as glaucoma or prostate problems, so it's important to discuss any pre-existing conditions with a healthcare provider.