276 An Introduction to Medical Mycology 



(c) In infections due to Achorion schoenleini the color is greenish but 

 is usually less luminous than in infections due to Microsporum. 



2. Animal carriers (particularly kittens) of certain pathogenic fungi 

 may be detected by fluorescence of affected hairs, which when observed 

 under filtered ultraviolet rays have an appearance identical with that of 

 human hairs affected with the disease. (See section on tinea capitis.) 



3. Tinea versicolor shows an individualistic color sufficient not only to 

 establish the correct diagnosis but to determine the extent of the eruption, 

 even when it has faded so that its presence cannot be detected clinically. 

 Other fungous eruptions, such as tinea circinata, tinea cruris and dermato- 

 phvtosis of the feet, and the secondary eczematous and dyshidrotic erup- 

 tions of the hands and other parts, as well as infections with Monilia and 

 the deep fungous infections (sporotrichosis, actinomycosis, blastomycosis, 

 coccidioidal granuloma, etc. ) do not fluoresce in any characteristic fashion 

 when observed under filtered ultraviolet rays. 



4. Hairs affected by lepothrix fluoresce. 



5. Keratin fluoresces, and when it is increased more luminosity may be 

 seen. The palm is brighter than the dorsum of the hand. Normal teeth and 

 nails fluoresce brilliantly. The differentiation of certain diseases of the 

 nails is aided. Warts and keratoses show a bright fluorescence, while mol- 

 luscum bodies exhibit a dark center. 



6. Some fading and indistinct eruptions become clearer when observed 

 under filtered ultraviolet rays. An accentuation of the syphilitic roseola is 

 frequently apparent, and this finding is useful when the diagnosis is not 

 easily made, particularly when concomitant findings are not present. Len- 

 tiginous and pigmented lesions usually appear darker when seen under 

 filtered ultraviolet rays than when observed in ordinary light. 



7. Many inorganic substances fluoresce. When a drug such as salicylic 

 acid or a product such as petrolatum is present on skin examined under 

 filtered ultraviolet rays the underlying condition may be masked. 



8. Various fungous growths in culture may be distinguished by their 

 characteristic fluorescent colorations. These will be taken up in detail when 

 the different fungi are considered. 



It may be mentioned here that we have studied this method of deter- 

 mination of species of fungi for many years and can testify to its value 

 and specificity. The characteristic fluorescence of a fungus appears to be 

 its most stable feature, resisting so-called pleomorphic changes. Variants 

 of a species which may appear totally unlike are recognized to be related 

 by means of the appearance under the rays. It seems to us that the method 

 has been in use sufficiently long to prove of merit and should be more 

 widel) employed. 



