Comedogenicity of current therapeutic products, cosmetics, and ingredients in the rabbit ear.

Cosmetics continue to be used by acne-prone individuals. Often as more acne develops, more cosmetics are applied. In order to protect against this natural tendency, physicians should provide more patient information on the currently available products and ingredients. This presentation is designed to help in that effort. The data presented were gleaned from the rabbit ear assay, which is not an ideal animal model but is the best we have. If an ingredient is negative in the rabbit ear assay, we feel it is safe on the acne-prone skin. A strong, positive ingredient or cosmetic should be avoided. Ingredient offenders include isopropyl myristate and its analogs, such as isopropyl palmitate, isopropyl isostearate, butyl stearate, isostearyl neopentanoate, myristyl myristate, decyl oleate, octyl stearate, octyl palmitate or isocetyl stearate, and new introductions by the cosmetic industry, such as propylene glycol-2 (PPG-2) myristyl propionate. Lanolins continue to be a problem, especially derivatives such as acetylated or ethoxylated lanolins. Our most troublesome recent finding is the comedogenic potential of the D & C Red dyes. They are universally used in the cosmetic industry, especially in blushers. This may explain the predominance of cosmetic acne in the cheekbone area. All of these D & C Red dyes tested to date, the xanthenes, monoazoanilines, fluorans, and indigoids, are comedogenic. Actually, this is not surprising as they are coal tar derivatives. The natural red pigment, carmine, is noncomedogenic and can serve as a substitute for D & C dyes in blushers. Many finished products are comedogenic. Most troublesome to the dermatologists are the therapeutic tools that we use, such as Liquimat, Retin-A cream, Hytone, Staticin, Sulfoxl, Desquam-X, and Persadox HP cream. These should be reformulated. We have been unable to confirm that precipitated sulfur (U.S.P.) is a potent comedogen in the rabbit ear assay. Clinically, we still find sulfur quite effective as an adjuvant to the benzoyl peroxide therapy for the treatment of acne vulgaris. We would suggest that the bias against sulfur be reconsidered.

Experimental production of pulmonary granulomas. IV. Eosinophilic granuloma.

Pulmonary granulomas induced in rabbits by the endobronchial instillation of mycobacterial chemical fractions were re-examined for eosinophilic infiltration. Delayed type hypersensitivity reactions either of tuberculin type or of wax D type did not induce but rather suppressed eosinophilic infiltration in the inflamed area, although some peptidoglycans which are antigenic for the induction of immediate hypersensitivity and fatty acid fractions were weak stimulators of eosinophilic infiltration. Bacterial endotoxin, LPS, was a potent stimulator. It was found that some long chain fatty acids can cause severe eosinophilic infiltration in the induced granulomas. Arachidonic acid was the most active of those examined, so the activity of its metabolites was tested and PGE2 was found to be most active. As the eosinophilic infiltration was markedly suppressed in animals treated with a cyclooxygenase inhibitor (aspirin), the stimulators of eosinophilic infiltration were not fatty acids themselves but their metabolites, PGE2 and some others. The site of permeation of eosinophils from the circulation was found to be arteriolar in the inflamed lung. The granulomatous lesion with eosinophilic infiltration in rabbits is discussed to shed light on the aetiology of eosinophilic granuloma in the human lung.

Lanolin allergy: crisis or comedy.

Lanolin has been applied to human skin from at least Egyptian times. Its virtues as an emollient and vehicle for cosmetics and drugs have been extolled for centuries. 50 years ago, a fly was found in the ointment--the first case of lanolin allergy was reported (1). Since then lanolin has achieved considerable notoriety as a contact sensitizer. Dozens of articles in the dermatologic literature emphasize the high frequency of lanolin allergy. European dermatologists seem to have become especially sensitized to lanolin allergy. Medical students learn early on, that medicaments in lanolin bases are hazardous. Every novice knows that lanolin is a sensitizer! The nadir of lanolin's fall from grace has been reached in advertisements of topical drugs which emphasize the absence of lanolin in the vehicle. These denouncements by dermatologists have not slowed down the demand for lanolin. About 2 billion pounds of finished cosmetics contain lanolin or its derivatives. It is impossible to reconcile this expanding market with the apprehensions of skin doctors. It is my intention to review the history of lanolin allergy, to present experimental data on its contact sensitizing potential and to put the risk of lanolin allergy in perspective.