690 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS MR. A.M. NETHERWOOD: You have remarked upon the reactions which have been caused by plasters during patch testing. There has now been available on the British market for some considerable time a plaster which has a single component adhesive base and this produces far less reactions than the usual resin-rubber. This is very good for applying patch tests. THE LECTURER: A porous or a non-porous tape? MR. A. H. NETHERWOOD: It is less porous than the perforated tapes but more porous than the straight plastic film-covered tapes. MR. J. McL.PHILP: You have been very clear indeed about the pitfalls of the diagnostic patch test, and I understand that there has been an attempt to overcome some of the pitfalls, notably in Scandinavia, where collaboration between five derma- tologists has resulted in a very standard patch test. Do you see any possibility for a similar collaborative effort in this country, and do you consider that there is need for such collaborative work? THE LECTURER: There is a great need for the standardisation of patch testing. If the same sites, same bases and same tapes were used by all investigators, it would give a much more valid comparison of results. MR. N.J. VAN ABBg: Under the auspices of the Society we have been carrying out a collaborative patch test with about eight different laboratories, including a derma- tologist and some other medical collaborators. The results are currently being analysed with a view to publication in the Journal. This is, of course, a prophetic patch test scheme for primary irritants and we have not been attempting diagnostic patch tests for allergens, which I personally regard as the province of the dermatologist. Nevertheless, we do seem to have obtained some very interesting results in this collaborative study and look forward to publishing them very soon. MR. C. PUGH: Is the incidence of primary irritations more prevalent in the summer than in the winter? THE LECTURER: I do not think this is really known. This question is often raised, but clinically we do not notice a seasonal variation. Theoretically, increased sweating in the summer, with hydration of the stratum corneum, should facilitate penetration of chemicals, so that the incidence of sensitivity might be expected to rise. If such a difference does exist it would need a very detailed study to detect it. MR. N.J. VAN ABBg: Do you really think that berloque dermatitis is something that deserves a clinical description? Are the reactions which are diagnosed as berloque dermatitis anything to worry about? THE LECTURER: They are nothing to be worried about this is a very distinctive clinical picture of patterned brown patches, usually on the neck, where the perfume has trickled down. The appearance simulating a pendant] or hanging drop has given the condition its name. It does not mean that the next time a perfume is put on the condition will recur. The persons are not allergically sensitive to the per- fume. MR. D. E. BUTTERFIELD: How frequently do you see this? I once knew, for example, a Hungarian girl who tried to use bergamot regularly for acquiring a tan. TuE LECTURER: It is not a very common condition but one that is easily recognised. I do not have any figures on the exact incidence.

CONTACT DERMATITIS FROM COSMETICS 691 DR. K. SA•aES: You attribute berloque dermatitis to the presence of phototoxic chemicals, probably psoralens in the perfume. The authors of the older textbooks used to attribute berloque dermatitis to the presence of traces of copper in the oil of bergamot employed in the perfumes, picked up either during distillation in copper plant or through transport in copper containers (always referred to in the trade as "coppers" irrespective of whether they are made of the metal or not). Indeed it is believed that considerable alterations to the distillation process, and certainly the tinning of coppers and their subsequent replacement by tinplate, were influenced by this traditional belief and the effects of these traces of copper derivatives through the use of perfumes in which bergamot was employed. Would you say that this theory is now obsolete in view of your remarks regarding phototoxic chemicals? T•tF. LECTURER: I did not know that copper had been thought to be the cause. It is the furocoumarin in the perfume which causes this photosensitivity. MR. D. E. BUTTERFIELD: Have you tried rectified bergomet? TI•E LECTURER: Trying to reproduce a berloque dermatitis experimentally is difficult. I have only seen this reaction reproduced in a patient who rubbed a rue leaf on her arm, went out into the sun and developed a marked erythema at the site. Haber (11) reproduced berloque dermatitis by applying the perfume under an occlus- ive dressing and produced an erythema on exposing the site to sunlight. MR. rA. FOSTER: One often gets a query from the public- do your cosmetics contain Orris? Frequently the writer states "my doctor suggests that it might contain Orris". Can you throw any light on this perpetual query? We know it is a known allergen but has any work been carried out on determining the presence of Orris, and its present-day importance? TuE LECTURER: I was under the impression that it was not used today. I think the statement that Orris can be dangerous just gets handed on from one person to another but I have never seen any reaction to it, and never known it to be used. MR. A. FOSTER: This is precisely the point I wish to make it is time that this bogey be abolished.