Yes you can use the medical card to get treated for ENT related illness PROVIDED the medical card has surpass the Specified Illnesses clause of 120 days waiting period.

General Exclusions:

Specified Illnesses occurring during the first 120 days of continuous cover for:
1. Hypertension, diabetes mellitus and Cardiovascular disease;
2. All tumours, cancers, cysts, nodules, polyps, stones of the urinary system and biliary system;
3. All ear, nose (including sinuses) and throat conditions;
4. Hernias, haemorrhoids, fistulae, hydrocele, varicocele;
5. Endometriosis including disease of the reproduction system; or
6. Vertebro-spinal disorders (including disc) and knee conditions.