Yaws

Yaws is a tropical disease of the skin caused by treponema pallidum subspecies pertunue.

It is spread by direct skin contact with an infected person or insect bite.

Yaws presents as:

• an initial papule/papilloma that may persist for 3-6 months
• if untreated, a late stage with multiple lesions, disfigurement of nose and bones and palmar/plantar hyperkeratosis.

Diagnosis is by dark light microscopy, rapid plasma reagin (RPR) or VDRL.  Note that it and syphilis give the same positives due to the close relationship of the causative organism.

Treatment is a single IM injection of benzylpenicillin.

References
WHO. Yaws. Fact sheet no 316. Available at http://www.who.int/mediacentre/factsheets/fs316/en/
Yaws again. Br Med J. 1980; 281(6248): 1090-1.