Brownish-Red Splotches on Inner Thighs

I have had brownish-red splotches on my inner thighs for a few months now.  I asked my doctor about it before I moved from the US and he told me that it was common and wrote me a prescription.  In the hassle of moving, I never got the prescription filled and have since forgotten the name of the medication.  My doctor never told me the name of the ailment, so I am at a loss as to how to treat it.  I live in an area where medical care is hard to come by.  The rash does not itch, burn, or affect me beyond it being unattractive.  It is isolated to the groin area.  

Thank you for your help!

[Dr_Aparna]

Hi,
Any activity that requires skin to repeatedly rub against skin can lead to chafing. And moisture, either from sweat or rain, makes the problem worse. Some common chafing sites are the inner thighs and under the arms or breasts.This friction can over time cause skin discoloration.
Acanthosis nigricans is a skin disorder that results in velvety, light-brown-to-black markings that can occur in any location but mainly are found in the skin folds of the neck, armpits, groin, and under the breasts.
The most effective treatment is obtained through weight loss and exercise. Eating a healthy diet can help reduce circulating insulin and can lead to improvement, and sometimes resolution, of the skin problem.
Other treatments to improve skin appearance, including Retin-A, urea, alpha hydroxy acids, and salicylic acid prescriptions, may be helpful in some people.
ref:http://my.clevelandclinic.org/disorders/Acanthosis_Nigricans/hic_overview.aspx