The condition affects about 1.3 million people worldwide, mostly in sub-Saharan Africa, but also in India and elsewhere.
The disease is estimated to affect one in 20 people worldwide and has killed more than 1.6 million people since its diagnosis in 2004.
Experts say the most effective treatment is a topical corticosteroid cream or a combination of both.
Corticosteroids are used to treat a wide range of conditions, from psoriasis to cancer, but the drugs have had some problems.
In 2010, the FDA banned the use of corticostomy medications in patients with the disease.
Critics say the new FDA guidance does not adequately explain the risks of the drugs, including side effects.
Many experts say they worry the new guidance could make it harder to find a treatment for the disease, and the number of people who have the disease has increased.