hi , my son aged 13 years had cold & cough . Due to excess wiping of nose, the skin there got nasty and he used dirty cloths to wipe out . as a result his upper lip and cheek got swollen , although no pain . I think it is some kind of infection . Dr has prescribed Azithral -500 , once daily for six days . His weight is 40 kgs. kindly guide whether this is right . He has also prescribed Betadine ointment .