138 An Introduction to Medical Mycology 



are the cleanest and probably the most efficacious. It should be remem- 

 bered that chrysarobin is a cutaneous irritant and should be confined to 

 the nail. Unless care is exercised that none comes in contact with the 

 eyes, conjunctivitis may occur. As with all applications, the old medica- 

 ment must be scraped away before any more is applied. 



2. Salicylic acid is combined with benzoic acid in a salve (double- 

 strength Whitfield's ointment), the proportions usually being 6 per cent 

 of the former to 12 per cent of the latter. The obvious disadvantage of 

 any ointment is that a great part of it is rubbed off; its use therefore is 

 not only wasteful and unpleasant but somewhat ineffective. In order 

 that these objections may be overcome, the surrounding skin should be 

 covered with petrolatum and an adhesive finger cot should be applied 

 to cover the entire end of the finger. Another useful application is a 40 per 

 cent salicylic acid plaster cut out to fit the nail and changed daily. We 

 can attest to its efficiency and cleanliness. 



3. Resorcinol alone is not of much value, but it is useful in combination 

 with other drugs. 



4. Thymol is a strong fungicide. Its use on the skin may be attended 

 with considerable reaction, but one need not worry over that effect in 

 the treatment of nails. Thymol (2 to 5 per cent) may be combined with 

 resorcinol (10 per cent) in an ointment and applied under adhesive 

 covering, as mentioned previously. 



5. Gentian violet and other dyes are not particularly efficacious in treat- 

 ing most cases of onychomycosis due to a species of Trichophyton. 



6. We do not advise the use of copper sulfate as a soak to soften the 

 nail. It has been recorded that in some instances gangrene has resulted 

 from this treatment. In general we do not approve of the use of medicinal 

 wet applications under an occlusive dressing for long periods, such as 

 overnight. Softening of the nail may be partially secured by the careful 

 application of potassium hydroxide ( 10 to 20 per cent ) . This may precede 

 by half an hour or more the application of one of the remedies mentioned. 



Finally, the patient should be made to realize at the outset that cure 

 will require his faithful co-operation. Several months' therapy is usually 

 necessary before all the fungi are destroyed. 



(1) Prophylaxis.— The problem of prevention of infection with a patho- 

 genic dermatophyte is difficult to solve. Many dermatologists believe that 

 attempts to prevent infection are useless. It is their opinion that all the 

 measures to be described and discussed here are of no avail and may even 

 be harmful as tending to shift the emphasis to procedures which are time- 

 consuming and of dubious benefit. The majority of uninfected persons are 

 unwilling to be discommoded in any way when they have little conception 



