Possible Mechanism of Crude Coal Tar Therapy in Infantile Eczema. ∗

Abstract

The therapeutic value of ointments containing crude coal tar in infantile eczema has long been recognized. It is not infrequently noted in eczema cases showing extensive skin eruption that untreated areas, as well as those to which direct application of the tar is made, improve. This suggests that crude coal tar may have a systemic as well as a local effect.

In the light of the observations that the serum fatty acids of infants with eczema are less unsaturated than those of normal subjects of the same age 1 and that administration of oils high in unsaturated fatty acids causes an increase in the degree of unsaturation as well as a clinical improvement in the condition, 2 a preliminary study of the effect of local applications of tar ointment on the fatty acids of the serum has been made. Data from 3 cases followed over a period of several months are presented here.

Case 1, an eczematous male infant 15 months of age, showed values of 334 and 322 mg. iodine absorbed per 100 cc. of serum on 2 successive days at the height of an outbreak of eczema. Eight days after local treatment with crude coal tar ointment the patient had improved clinically and the iodine absorption had risen to 486. One and 2 months later the values were 494 and 520 respectively and the condition remained good. In subsequent cases the iodine number of the serum fatty acids was studied.

Case 2, an infant 5 months of age with severe eczema, was found during the active phase of the disease to have an iodine number of the serum fatty acids ranging between 79 and 81. After application of coal tar ointment for one week, which caused marked improvement in the condition of the skin, the iodine number was found to be 109. At the end of the second week of treatment it was 95 and two weeks later was 101. Active treatment was then omitted for 3 weeks, during which the skin remained entirely clear, except for the appearance of a slight eruption in the folds of the neck. The iodine number at the end of this period was 113.

Case 3, a 6-months-old infant with severe eczema showed an iodine number of the serum fatty acids of 78 before the ointment was applied. This had risen to 96 at the end of a 10-day period of treatment during which the lesions showed marked improvement. Four weeks after the tar was stopped the iodine number had again fallen to 84 and in 5 weeks it was found to be 76.