TINEA TONSURANS. CIRCINATE RINGWORM. 



Common in the young — man and animal ; transmissible from one to the 

 other ; early observations of this. Trichophyton tonsurans in deep layers 

 of concretion, hair follicles, bulbs and stems ; spores round, refrangent, 

 largest in horse and ox ; filaments vary in size, protoplasm, membrane, seg- 

 mentation, chains of spores ; hairs break across, split, drop out ; baldness. 

 Trichophyton endothrix in human hair only. Trichophyton ectothrix out- 

 side the hair on animals and man ; has smaller spores than endothrix. 

 Probably varieties and interchangable. Accessory causes : Youth, confine- 

 ment, close, dark, damp stables, moulting, abrasions, vermin, morbid skin 

 exudates, crowding, common blankets, buildings, vehicles, posts, halter, 

 harness, lack of grooming, contact of sick and healthy, dust. Susceptibil- 

 ity. Symptoms : Red papule, grows to round scaly spot, hairs erect, 

 broken, split, all drop, those around bleached by chloroform, new spots 

 form, progressive extension. Cattle : On head and neck mostly, thick on 

 dark skins, one or two inches in diameter ; under scurf, red, tender ; itch- 

 ing slight ; number attacked ; attendant. Horse : On dorsal aspect mainly, 

 rare on limbs ; hair erect in tuft, scurfy base, then depilation, surface 

 moist or dry, smooth, slaty ; new hair causes dappling. Dog : Mostly on 

 head, legs, feet ; erect tuft ; thin, bare scurfy spot ; matting of adjacent 

 hair by serum or blood ; itching ; white glistening skin, swelling. Cat: 

 Mostly on face and paws (from mice) ; erect hairs in circle, depilation, 

 bald spot, ^ to I inch. Sheep : On back, head or neck, as in cattle, or 

 flattened tufts of wool with excess of scurf, shedding of wool, hangs in 

 white tufts ; itching. Goat. Pig : Scurfy spots one inch across, red, 

 scaly; depilation; dry centre, moist margins. Birds: Congestion, scurf, 

 depluming. Trichophyton epilans : More rapid growth, more destructive 

 to hair. Tonsurans cultures show snowy tufts and little liquefaction of gel- 

 atine ; epilans yellow pellicle and rapid liquefaction. Inoculation with skin 

 products or cultures easy and successful, between genera. Prognosis good, 

 except in neglected and cachectic. Prevention . Segregation of sick and 

 well ; oiling ; use of separate articles in grooming, etc. ; disinfection of 

 brushes, combs, etc., by sublimate, iodine, carbolic acid ; vitality of germ. 

 Treatment : Depilation and burning ; tar ; carbolic acid ; sublimate ; 

 creolin ; naphthalin ; salicylic acid ; iodine ; iodized phenol ; oil solvents ; 

 clipping ; shaving ; hair extraction, cocaine ; unguents ; unguentum 

 hydrargyri ; balsam of Peru ; copper sulphate ; red precipitate, etc. 



This aifection is especially prevalent in children (3 per cent, in 

 city common schools) and in the young domestic mammals. It 

 is the direct result of the colonization of the skin by the crypto- 

 gam — trichophyton tonsurans In Auvergneit was recognized 

 as communicable from animal to man as early as 1831 (Grognier), 

 2 17 



