Hello Doctor, i am pravalika of age:15yrs, ht:5.4, wt:45kgs.since from last 4 yrs iam facing badly the problem of black patches on my body(back side to neck) which is exactly known as "tinea versicolor".so iam using Novale soap &Derma dew soap & onabet liquid, even though the result is poor.pls suggest best remedy to avoid it completely,i will be very thankful for ur quick response.