Hello there! Thank you for the question. As you have mentioned, you have been experiencing flu, sore throat, fever, headaches and you are also allergic to dust. There is a high possibility that you are experiencing allergic rhinitis. Allergic rhinitis, or hay fever, is an allergic response to specific allergens and pollen are the most common allergen followed by dust mites.

Symptoms of allergic rhinitis includes sneezing, runny nose, stuffy nose, itchy nose, coughing, sore or scratchy throat, itchy eyes, watery eyes, dark circles under the eyes, frequent headaches, eczema-type symptoms such as having extremely dry, itchy skin that can blister and weep, hives and excessive fatigue. So what causes allergic rhinitis? Well when our body comes in contact with allergens, it releases a natural chemical called histamine which causes the symptoms such as runny nose, sneezing and itchy eyes.

This condition can affect anyone but you’re more likely to develop allergic rhinitis if there is a history of allergies in your family. Conditions such as asthma or atopic eczema also increase your risk of allergic rhinitis. There are many external factors which can aggrevate this condition including cigarette smoke, chemicals, cold temperatures, humidity, wind, air pollution, hairspray, perfumes, colognes, wood smoke and fumes.

As you have mentioned you have been taking Zyrtec which is an antihistamine. It will help reduce your flu and inflammation of your throat. As for your fever, you can take paracetamol 500mg every 4 hours to reduce your fever and heachache. If your condition does not improve it is advisable to consult a doctor. All the best!