The Superficial Mycoses 131 



a hast) application is almost useless. In many cases the preparation may be 

 kept on the part day and night, being reapplied two Or three times during 

 the 21 hours. 



1. A clean, efficient application tor localized scaly noninflammatory inter- 

 trigo consists ol 1 per cent tincture ol iodine. The majority of persons ma) 

 use this daily without its causing irritation. 



2. Compound ointment of benzoic acid (Whitfield's ointment) is made 



as follows: 



Benzoic acid 5 per cent 



Salicylic acid 3 per cent 



Soft paraffin 25 per rent 



Coconut nil ad. 100 per tent 



In hot climates 2 to 4 per cent hard paraffin may be added. This is the 

 ointment as originally advised by Whitfield. In this country the salve is often 

 compounded in the following manner: 



Salicylic acid 3 per cent 



Benzoic acid 6 per cent 



Hydrous wool fat, and , 



Petrolatum aa p.e. 



This is referred to as "full strength." If there is considerable inflammation 

 (but no vesicles) it may be used half-strength or even quarter-strength. If 

 one desires a strong keratolytic effect it may be prescribed in double or 

 triple strength. In general, this prescription, or a modification (to be men- 

 tioned ), should be used only on the interdigital webs, the palms or the soles. 

 On the dorsa of the feet, on the glabrous skin or on the backs of the hands it 

 too frequently produces secondary inflammatory changes (which often be- 

 come eczematous ) to allow of its indiscriminate use on these parts. 



Various other drugs may be added to modify the formula, the most 

 commonly employed being iodine and chrysarobin. Both increase the irri- 

 tability of the skin. It is advisable to begin with 1 per cent iodine or 0.25 per 

 cent chrysarobin, later increasing the strength of either or both. 



The vehicle also may be changed. White wax (2 to 10 per cent) may be 

 added to diminish softening, particularly in hot weather. If alcohol is used, 

 the strength of the active drugs should be decreased by one-third or more; 

 a strength of 2 per cent salicylic acid and 3 per cent benzoic acid will be 

 found potent. Aqueous solutions are not possible, owing to insolubility ol 

 the drugs. 



3. A modification of Dreuw's ointment according to the following formula 

 is sometimes very effective. 



Rectified oil ol birch tar per cent 



Chrysarobin 1 per cent 



Salicylic acid per cent 



Soil soap, and 



Wool fa1 aa 12 per cent 



