Hello
As your husband is having fever ( low grade ) from last 2 months with
sore throat . In my opinion however it is very difficult to establish any diagnosis with this short history but allergy is not responsible for such type of fever. Usually allergy is another sort of problem causes
bronchoconstriction ,hence cough and cold may be due to allergy.
If infection is there , this may cause fever . In your husband the duration of fever is very long . This is a cause of concern .
As you husband is also having swollen testis , cold , weakness , fatigue .
Weakness and fatigue may be due to fever .
The possibilities of fever may be , these include .
1
Orchitis inflammation ( infection )of testis sometimes develops such type of
low grade fever . So consult a physician / surgeon and get his opinion because physical examination is important in this case. If there is fluid collection in sac of scrotum ( testis ) it don't produces fever.
2
Tuberculosis , this is another most common cause of prolonged duration fever . Get in sputum examination for A F B , blood for E SR , X ray chest , montox test .
3
Typhoid fever is one such cause of low grade fever . Get in
Widal test as well serology test for confirmation.
There are so many other causes of fever as anemia , tumor in lungs , abdomen .
But deal as mentioned above.
Good luck.