Viral fevers are known to be debilitating and sap a person's energy quickly. They manifest as anything from colds, to cough
, to fever, to gastric disturbance and body aches. Altered taste
in the mouth, or in your case, metallic taste
is one of the symptoms of a viral infection because a virus can affect your sense of taste.
Also, since you are an asthmatic, it is also possible that this added infection has caused you to breathe predominantly from your mouth making it dry, thereby giving a metallic tinge. Dehydration
is also known to affect taste buds
Just make sure you drink lots of fluids, eat healthy meals and get adequate sleep and rest.
All the best!