RESUMEN
1. A brief histological report on 66 skin-biopsy specimens of the primary lesions of leprosy from very young children of leprous parents - children from 13 to 39 months - is made2. Clinically, these 66 primary lesions, when first seen, were wheal-like, papular, slightly raised or thickened area, scar-like, nodular or rounded area, granular or rough area, hypertrophied follicles, or pinhead hypopigmented area. Fifty-five lesions had the first three characteristics; only 11 had the last five3. These lesions were very small - 50 of them measuring only from one to five mm. in a diameter, 15 from plus five to 10 mm., and only one 15 x 25 mm4. Leprosy bacilli were demonstrated in varying numbers in 49 cases or 74.2% of the 66 specimens studied5. Tuberculoid histology was demonstrated in 50 specimens, while in 16 the lesions consisted of histiocytic infiltrations, with varying collections of lymphocytes - the so-called indeterminate or undifferentiated type of lesion6. Leprosy bacilli in varying numbers were demonstrated in 37 or 74% of the 50 specimens with tuberculoid histology; they could not be demonstrated in 13 or 26%7. Leprosy bacilli were demonstrated also in the sections in 13 or 81.25% of the 16 specimens with the undifferentiated type of lesions8. The history of previous regional skin blemishes in relation to the lesion sites of biopsy is pointed out to help explain the possible manner of infection9. A total of 162 primary lesions were identified clinically in these 66 children. As many as from 1 to 7 lesions in each child were recorded, mostly localized in the uncovered portions of the body. This strongly suggests that the skin is the probable site of entry of the leprosy bacillus10. The mechanism of infection of the skin by the leprosy bacillus through the agency of the leukocytes, which respond to the site of injury, is discussed, based on known microscopic inflammatory processes of tissue repair following injury11. Fifty-two of the children are living and are still under regular observation in Culion. They are now adolescents, varying from 11 years 7 months to 16 years 3 months old. Only three or 5.8% of these children have developed the disease. The remaining 49, or 94.2%, have remained "clean" as far as the leprosy disease is concerned, despite their continous exposure in the colony, a highly leprous environment12. This is contrary to recent beliefs of some workers concerning the lack of resistance of infants and young children to leprosy13. It is concluded that a child may become infected with leprosy; but probably because of a relatively high degree of individual or native resistance in them, the first infection is overcome and eradicated through natural processes14. None of the 66 children were given any anti-leprosy treatment throughout the period covered by these observations, and the clearing up of the infection can be attributed to no other cause than to the natural or native individual resistance of these children, since they failed to develop clinical leprosy up to their adolescence.(Summary and Conclusions)