Yaws is an infection of equatorial & west Africa, Latin America, Caribbean islands, SE Asia, and South Pacific islands. It begins as a painless papule (mother yaw) on face or extremity (usually leg) that evolves over weeks to months into a raspberry-like or ulcerated lesion several cm in diameter.
CASES/YEAR
0 (US); 460,000 (Global)
OTHER NAMES
Endemic treponematoses; Endemic syphilis (Related Infection); Pinta (Related Infection);
INCUBATION
10-90 days; Average of 21 days; [CCDM]
INITIAL SYMPTOMS
Yaws: Painless papule (mother yaw) on face or extremity (usually leg) that evolves over weeks to months into a raspberry-like or ulcerated lesion several cm in diameter. Bejel: Ulcerations of the mouth and angular stomatitis; Pinta: skin lesions;
PRECAUTIONS
"Until lesions are healed, patients should be advised to avoid intimate contact with others and contamination of the environment." [CCDM, p. 682]
COMMENTS
FINDINGS:
The initial raspberry-like lesion in yaws begins as a papule that slowly enlarges. It is usually located on the lower extremities. Tender regional lymphadenopathy may accompany the primary lesion. Fever is uncommon. [PPID, p. 2894] Unlike syphilis, the spirochetes do not cross the placenta or blood-brain barrier. Broken skin is the route of entry. [Cecil, p. 1990] As the mother yaw disappears, satellite papillomata appear in successive crops. Associated symptoms at this stage may include flu-like symptoms and inflammation of shin and finger bones. Palms and soles may be affected by painful papillomata and hyperkeratoses. After five or more years of infection, destructive lesions of the skin and bone occur in 10%-20% of untreated patients. The disease is spread by direct skin contact, and flies may transmit some infections. "Almost all cases occur in children younger than 5 years . . ." [CCDM, p. 679-81] Like leprosy and leishmaniasis, yaws can cause destructive lesions of the nose, maxilla, palate, and pharynx. [Harrison ID, p. 670] Conjunctivitis may occur. [Guerrant, p. 1001] Yaws is primarily a disease of children. Late infections may cause lesions of the skin, bone, and joints. Yaws is associated with conjunctivitis and uveitis. [Guerrant, p. 293, 1004-5]
RELATED INFECTIONS:
In a typical case of endemic syphilis (Bejel), there is an inoculation papule and regional lymphadenitis. Complicated infections may involve the bones and joints but not the cardiovascular or neurological systems. Bejel can cause uveitis. [Guerrant, p. 292; 1000] Early skin lesions are papules and macules, often hypertrophic and circinate. Other skin findings are hyperkeratoses of palms and soles, alopecia, and patches of depigmentation or hyperpigmentation. [CCDM, p. 68] Disseminated papular rashes, similar to those of secondary syphilis, may occur. [PPID, p. 2895] Angular stomatitis is a finding in endemic syphilis and yaws. [Cohen, p. 964] Destructive lesions of the skin, face, and bones are more common in endemic syphilis than in yaws. [Harrison ID, p. 670]
Pinta, another endemic treponematosis, is caused by Treponema carateum. It presents as a painless papule in older children and adults. Regional lymphadenopathy is common. Papules evolve into blue, violet, or brown macules or plaques. The skin lesions heal with some scar tissue, and there are no complications. Pinta is near eradication in the American tropics with a few cases still being reported in Central America and Cuba. [CCDM, p. 455] Patients may have adjacent blue and white areas of skin. [Cecil, p. 1990]
DIAGNOSTIC
Darkfield or DFA microscopic exam; PCR; [CCDM, p. 680] Serological tests for syphilis (RPR, VDRL, & FTA-ABS) are positive if obtained at least 2 weeks after initial lesions appear. Point-of-care serology now available; [Cecil, p. 1990];
SCOPE
Equatorial and west Africa, Latin America, Caribbean islands, SE Asia, and South Pacific islands; [CCDM] Bejel: Dry regions of North Africa and Arabian peninsula; [Guerrant, p. 293] Pinta: Latin America; [Merck Manual, 1713]
SIGNS & SYMPTOMS
-
>fever
-
E nasal ulcers
-
E stomatitis
-
H lymphadenopathy
-
O conjunctivitis, acute
-
S entry wound with lymph nodes
-
S papules or plaques
-
S rash (exanthem)
-
S rash on palms
-
S skin or subcutaneous nodule
-
S ulcer of skin
-
S warty growth of the skin
-
*arthritis
-
*osteomyelitis
-
*uveitis
ENTRY
Skin or Mucous Membranes (Includes Conjunctiva)
TREATMENT
"For patients with active disease and their contacts, treat with a single intramuscular (IM) injection of benzathine penicillin G or single dose oral treatment with azithromycin." [CCDM, p. 682]
REFERENCES FOR CASES/YEAR
1.
2. (Global) Of the endemic treponematoses, yaws is the most common. [PPID, p. 2894] 1952-1964: Penicillin IM decreased cases from 50 million to 2.5 million; India eliminated disease in last 6 years using a single dose of azithromycin; [Fact sheets from WHO 2013] Campaign in 1952-1969 reduced incidence from >20% to <1% in some areas; WHO estimate in 1997: 460,000 new case of endemic treponematoses every year; [Harrison ID, p. 668]