Fig. 121.—Yaws. This case shows an abundance of yaws tubercles on face. Distribution on trunk and extremities less extensive. (From Ruge and zur Verth.)
The Primary Stage.—During a period of incubation, averaging three weeks, vague digestive troubles, nocturnal headache, joint pains and an irregular fever may be noted which often abate upon the appearance of the initial papule at the site of inoculation. There may be enlargement and tenderness of the lymphatic glands about the time of the appearance of the eruption. This initial lesion may be single or there may be several papules grouped together. In some cases it may be impossible to get any history of a primary lesion or it may have been overlooked. The primary lesion is almost invariably extra-genital and it has the same appearance as the lesions of the secondary stage, thus differing from syphilis.
Fig. 122.—Child with yaws. (From U. S. Naval Medical Bulletin.)
The yaws lesion, whether primary or secondary, starts as a papule which in a few days enlarges to the size of a small pea. It is conical and surrounded by an inflammatory areola. At this time the thickened epidermis begins to crack and a yellowish sero-purulent fluid exudes from the underlying fungoid base. They bleed easily but are not painful. It is this fungoid yellowish or yellowish-red tubercle which has been thought to resemble a raspberry, hence the name framboesia. French authors liken it to a fig which has been turned inside out. The moist or crusting surface soon shows an underlying ulcer, which may dry up leaving a pigmented spot or become exuberant and appear as a mass of fungating granulations, 1 to 2 inches in diameter. Such lesions are given the name “mother yaw.”
The Secondary Stage.—In from six weeks to three months after the appearance of the initial lesion, which may have dried up and left only a scar, or which more commonly is still present, there again set in malaise, headache and joint pains with an irregular inconstant fever.
The secondary eruption is made up of lesions having the same character and course as the primary yaws tubercle. In the general eruption, the papules appear frequently in the region of the junction of skin and mucous membrane as about mouth, nose and anus. In such regions they may become very moist and resemble the mucous patches of syphilis.
Besides their location on face and about the perineal region they are numerous on neck, arms, legs, and buttocks. They are rare on the trunk and scalp.