Avil (pheniramine maleate 25 mg) can be used for urticaria in adolescents but should be given with caution and after checking for contraindications and other medicines being taken.

💊 Safe use and dosage

• Common practical approach: a single Avil 25 mg tablet orally may relieve mild hives; some clinicians use 25–50 mg every 4–6 hours as needed, not exceeding about 300 mg/day.
• Avil (a prescription medicine in India) should be used only as directed by a doctor.

⚠️ Warnings and side effects

• Drowsiness, dizziness, dry mouth are common—do not allow activities requiring alertness until effects are known.
• Avoid alcohol and other sedating drugs; avoid if taking monoamine oxidase inhibitors (MAOI) (monoamine oxidase inhibitors).
• Use caution with uncontrolled narrow‑angle glaucoma, significant prostate enlargement with urinary retention, or severe heart/lung disease.

🩺 What to do now (action steps)

• Give a single 25 mg tablet now if the rash is itchy but breathing is normal, and observe for drowsiness or worsening symptoms.
• Stop additional antihistamines or sedatives until you confirm safe combinations with a doctor.
• See a pediatrician or a dermatologist/allergist promptly to confirm dosing, check for triggers, and get a prescription if needed.

⚠️ Red flags — seek emergency care immediately

• Difficulty breathing, swallowing, or noisy breathing
• Swelling of face, lips, tongue, or throat
• High fever, fainting, severe confusion, or unresponsiveness

If you want, I can provide a short checklist to share with the doctor before you call.