Brit. J. vener. Dis. (1971) 47, 223 Br J Vener Dis: first published as 10.1136/sti.47.4.223 on 1 August 1971. Downloaded from Neuro-ophthalmological study of late yaws I. An introduction to yaws J. LAWTON SMITH From the Department of Ophthalmology, University of Miami School of Medicine, Miami, Florida, U.S.A. Three major forms of treponemal disease are found patchy distribution in hot and humid regions. in man: syphilis, due to Treponema pallidum; yaws, Dark-skinned children under 10 years of age who due to Treponema pertenue; and pinta, due to live in rural areas are more commonly involved. Treponema carateum. The spirochaetes that cause Poor hygiene and lack of personal cleanliness pre- these diseases are morphologically indistinguishable. dispose to the disease. The incidence is slightly higher Furthermore, the diseases cannot be differentiated in boys than girls, perhaps because of the higher by any known serological test or therapeutic criterion. incidence of skin abrasions in the former. The in- Only two ways are now known by which the trepone- fection is spread by direct contact, and also by soiled matoses can be differentiated: clothing and bedding. According to the literature, (1) Clinical criteria; yaws is not venereal and not hereditary. The disease (2) Experimental infection of laboratory animals or is divided into primary, secondary, and tertiarycopyright. human volunteers. stages, which are also designated initial, early, and The rising incidence of infectious syphilis in the late stages in the Hackett classification. Yaws is said to United States, the usefulness of the FTA-ABS test in involve only the skin, mucous membranes, bones, diagnosis of late 'seronegative' syphilis, and the detec- and joints, and visceral lesions are said not to occur. tion of treponemes in human aqueous humour and Although monkeys, hamsters, and rabbits have been cerebrospinal fluid have recently given impetus to the infected with yaws experimentally, the only natural reservoir of the disease seems to be man. study of late ocular and neurosyphilis. Ocular and http://sti.bmj.com/ neurological involvement are common in late syphilis and are well recognized, but such involvement is said Clinical course not to occur in either yaws or pinta. This contrast The initial lesion, after an incubation period of 2 to 8 prompted a cooperative neuro-ophthalmological weeks, is called the 'mother yaw'. This is usually study of late yaws and pinta between the Department single and is found on parts of the body exposed to of and trauma, often the legs or buttocks. Non-immune Ophthalmology of the University of Miami, mothers carrying children on their backs may de- the on September 30, 2021 by guest. Protected National Institute of Venereology in Caracas, velop lesions on the flanks from contact with yaws on Venezuela. Because of the lack of familiarity of The most English-speaking physicians with the tropical, the infants legs. initial yaw begins as an erythe- non-venereal treponematoses, the purpose of this matous papule that rapidly becomes granulomatous, as a and becomes covered with a crust of dried exudate. report is to provide a brief introduction to yaws lesion reaches 2 to in disease entity as obtained from the literature (Biggam The pinkish-yellowish 5 cm. and with diameter in one or more weeks, and may remain Wright, 1964; Felsenfeld, 1965) emphasis solitary for 1 to 3 months. There is usually some on late aspects of the disease which are of neuro- degree of regional lymphadenopathy. ophthalmological interest. The secondary eruption usually begins 3 to 6 weeks Yaws, also known as pian or framboesia, is a later, sometimes before the primary lesion has disease of certain tropical countries in Central and healed. Papillomata, often occurring in crops, becomc South America, Africa, and the Far East. The causal very numerous in moist flexure surfaces and around agent, Treponema pertenue, discovered by Castellani the mouth. These lesions are highly contagious. (1905), is morphologically indistinguishable from the Those around the mouth and nose are usually moist agents causing syphilis and pinta. Yaws occurs in in appearance, whereas those of the palms and soles are dry and hard, often with numerous fissures and a Received for publication January 5, 1971 tendency to ulcerate. If such a lesion erupts Paper read at the International Colloquium on Late Treponematoses, through Miami Beach, Florida, January 4-8, 1971 the sole, walking becomes painful and the resultant 224 British Journal of Venereal Diseases Br J Vener Dis: first published as 10.1136/sti.47.4.223 on 1 August 1971. Downloaded from gait led to the term 'wet crab yaws'. Bony involve- Osseous changes in late yaws are important. ment often causes the fingers to become swollen and Radiological examination of the long bones may show sausage-like. A similar involvement of the long localized areas of rarefaction with surrounding bones may cause sabre tibia. Swelling of the nasal periostitis. These may present clinically as localized bones is called a goundou. Early mucosal yaws may bony swellings, and the overlying tissue may ulcerate be maculopapular or papillomatous. This is most and resemble a gumma. Bony involvement in the commonly seen in continuity with skin lesions of hands, outer table of skull, nose, and palate is not mouth and nose. Other lesions of early yaws include a uncommon. variety of skin eruptions, synovitis, periosteitis, The milder cases, which are more common, may hydrarthrosis, and diffuse ganglia. show a sunken nasal bridge or small palatal perfora- Healing of the skin lesions begins with clearing of tion. In extreme cases, gross mutilation may make exudate, followed by loss of the crust. There is the nose and mouth one open cavity (gangosa). Such usually no scar, except after heavy secondary in- lesions, with distortions of bones, contraction of fection, but hyperpigmentation may result and may joints, ulceration, and scarring, may produce a last for years. tragic clinical picture. Other late manifestations of yaws include hy- Laboratory studies drarthrosis, bursitis, and firm, painless subcutaneous The serological tests for syphilis, including both juxta-articular nodules, usually found near the reagin (VDRL) and treponemal (TPI and FTA- elbows, hips, and knees. ABS) tests, become reactive, and so do not help to From the neuro-ophthalmological point of view, differentiate syphilis, yaws, and pinta. Histopatho- yaws would appear from the consensus of the litera- logical differentiation of the lesions may likewise be ture, to be an unrewarding disease to investigate. difficult, as the changes differ primarily in degree. Biggam and Wright (1964) stated: copyright. The initial yaw and the secondary lesions, histologi- 'Unlike tertiary syphilis, yaws does not affect the cardio- cally, are proliferative granulomata with numerous vascular system or internal viscera, and the only neuro- treponemes. Syphilitic lesions are said to show only logical changes are very minor alterations of the cere- moderate acanthosis, no gross inflammation in the brospinal fluid'. dermis, and proliferative changes in intima and media Medina (1963), the world authority on the disease, of vessels. In contrast, yaws lesions tend to show stated: marked acanthosis, more marked inflammation in the 'Nowadays, it is agreed that only syphilis can bring http://sti.bmj.com/ dermis, but no proliferation of intima or media of about visceral changes, particularly of the nervous system vessels. and the aorta, and can establish itself in the placenta, thus giving rise to congenital syphilis. Yaws can never bring about these pathological conditions'. Latent and late yaws The mention of minor alterations in the cerebro- After the spontaneous resolution of early yaws, there spinal fluid arouses interest. A few voices of dissent is usually a latent period during which serological have been recorded. In a paper entitled 'Hereditary changes may persist in the absence of clinical signs. Yaws', Leon (1929) stated: on September 30, 2021 by guest. Protected Tertiary lesions usually develop 5 to 10 years after 'In speaking today on the subject of congenital yaws, I infection, but it should be noted that not all patients am aware of the rashness of discussing a condition which develop late yaws. The commonest manifestations of is said not to exist both by the older classical medical late yaws are cutaneous. Nodular lesions develop texts and by more recent literature'. which ulcerate and spread superficially, and at times Leon observed that Stitt (1922) had stated: 'It is penetrate deeply into the underlying tissues. These quite obvious that there does not exist a congenital can produce gross deformity. The lesions oflate yaws form of yaws' and that Roussel had remarked: 'Yaws tend to heal with scarring in one site, even while the is neither hereditary nor congenital'. However, Bertin ulcer is extending in another direction. Another late (1786), after working in the French colony of San manifestation is hyperkeratosis with fissuring of the Domingo wrote that 'Yaws, as the venereal diseases palms and soles, known as 'dry crab yaws'. The and others, is transmitted through heredity'. Hunt location of late lesions is of interest. Late yaws may and Johnston (1923), after studying 2,000 cases in develop on the site of the mother yaw. A mother Samoa, described interstitial keratitis in hereditary with latent yaws nursing a child with early yaws of yaws. Leon (1929) concluded: the face may develop a tertiary ulcer of the breast. 'That yaws may be hereditary is possible. Fetal mor- These findings have suggested sensitivity and local tality appears to be about five times greater in syphilitic re-infection as factors in late yaws. than yaws cases'. Neuro-ophthalmology of late yaws. I 225 Br J Vener Dis: first published as 10.1136/sti.47.4.223 on 1 August 1971. Downloaded from The classic studies of Medina (1963), utilizing References experimental inoculations of treponemes into human BERTIN, N.