Black patches on the leg and watery eyes from allergies can be managed with a combination of skin care and allergy treatment. For watery eyes due to allergies, an antihistamine like cetirizine (found in Cetzine 10 mg tablets) can help reduce symptoms by blocking histamine, which causes allergic reactions.

For the black patches on your leg, these could be due to post-inflammatory hyperpigmentation or another skin condition related to allergies or irritation. It’s important to keep the area clean, avoid scratching, and use gentle moisturizers. Applying sunscreen can also prevent worsening of pigmentation.

• For watery eyes: Taking an antihistamine such as cetirizine as prescribed by a doctor can relieve symptoms.
• For black patches: Avoid scratching, keep the skin moisturized, and protect the area from sun exposure.
• If the patches persist, worsen, or are accompanied by other symptoms like pain or swelling, consult a dermatologist for evaluation and possible treatment.

Please consult an allergist or dermatologist to get a precise diagnosis and tailored treatment plan. If symptoms worsen or you experience difficulty breathing, seek emergency care immediately.To narrow down potential causes, we will need some more information.I understand you're looking for advice about black patches on your leg and watery eyes from allergies. To give you the best advice, could you please share your age and gender?