Document kDnJqVqMroyDqbDn8ENZr8r8V

FILE NAME: Z/ZZZ/Ed DATE: DOC#: /Ed DOCUMENT DESCRIPTION:>ZZ^ZZ Z EZDZZZZZ Z 1/f. ~424 THE_ LANCET, Vol. II for 1983 (December 17); No. 8364: 1424. ~C!;III ...~l Code TllELA}.;<;ET,DF.CE.\!.BER 17, l9$3 mineral tilter aids been us.:d in the past frw decades in sui,:Jr rdining in Swt1.lc:n? And do worker~ in such factories have :in increased incidence of g.istrointestin.il tumours and lung carcinom:is? lmporiJI C.mccr Rc'ICJt~h funJ, LonJon WC.\ lPX G. D, CLARKE c.R. H. ~E\\"M:\:\ H. O'!\EILL S.:nool of l'lnr Boology, l 0 n1virrs1ty Coll.:i:c or!':orrh \~~,~~. rBongor STANDARDS FOR ASBESTOS D. \"\1Y:\:\ EXPOSURE P.'>RRY SIR,-Your Routtd the World correspondent (Dec 3, p 1298), reporting on the US c:mergency standard for asbestos expoi;ure, states that attempts to modify current health standards "have been resisted by industry". This is not true. For some years now the US asbestos industry, through the Asbestos Information Association of North America (AIA/NA), has been trying to persuade the Occupational Safety and Health Administration to hold public: hearings so that the need for a revised standard could be properly investigated. The Administration took no action but has now suddenly (as your correspondent points our) imposed an emergency temporary standard whic:h c:irries 1.1.irhit implic:ationsofan C."<trcme us danger to the workforce in need ofan urgent remedy, which is quite at vari:inccwith the facts. courts subsequently suspcn~d this emergency temporary standard, pending funher evidence. Asbesaos lmmmional "-Wion, 68 Cilou.:nm l'bcc, LOCldon \\" l H ~!IL .,;.J NEVILLE STACK, tl1rccrot Gencnl IS MIGRAINE FOOD ALLERGY? S1R,-I was impressed with the results and scientific: rigour ofthe trial\ reported by Dr Egger and colleagues (Oct 15, p 865). Neverthel~ one point troubles me. Of88 children who completed the oligoancigenic: diet, only 40 wc:re randomised into the double- ~ blind trial. 28 children 1.11ere C.""<clu~d for a \"lll'iety of reasons, including "reacted to plac:ebo tin". \"<'hy were these children given a placc:bo tin? My understanding was that children were offered the plact:bo tin only after randomisation to the double-blind trial. -Children oficrc:d the active food had significantly more hc:adaches than did children offered tht: placebo tin; howc:ver, ifchildren who had reacted to tht: placebo tin were: systematically removed from the study it is easy to understand why the placebo effect would be so much less than that of the presumed active food. If any number of children who r.:ac:tcd. to th.: placebo food were rt:moved from the final analysis, the conc:lusions of this study reached by Egger ct al become: suspect. Dcparrmcnr orPo:dia1na. S.hool or Medicine, I:am:rsuy of Ouaw-, Ch11Jrcn's Hosp11al of Eulcm On1ario, Ouawa,Onl4rioK1118U,C..naJa WILJ.IA.\1 FELO.\IAN *.:This letter has been shown to Dr Egger and his colleagues, whose reply to it and to earlier comments follows.-ED. L S1R,-Professor Feldman has drawn attention to an imperfection in the text ofour paper, which resulted from editorial compression and from removal of the ac:compllnying table, which gave the reasons for the exclusions. Most refusals were because the parenLS were unwilling, despite previous agreement, in view of the remarkable improvement in their children; others because: children did not rr:act to foods for which we had tins; and only one bc:cause he reacted to some of the ingredients of both placebo tins, when these were introduced openly, one by one, in the reintroduction phase. \Y/c reject the suggestion of Dr Wilkinson and Dr Blau (Nov 5, p 1082) that our patients did not have migraine. As stated, patients were selected for severity and frequency and so the proportion of patients with complicated migraine was high; seizures in 15% is about twice the rate reported in an unselected series (6 5%). 1 The rc:commcndation that research be done on "straightforward cases of migraine" _is unsound. Such demanding treatment would be 1. Lcnnm. \\"G. l..l!nnft!t M.A. Enill!nn :and COMPLETE DATA 01" l'ATIE1'T P.ECRUlT.\IEl'T En1ered study 99 Completed oligoantigenic: ditl 88 Responded 82 Rc:bpscd on open provocation 74 Entered 1rial 46 Completed 1rial 40 or Did 111Jt m11r trial bauu: I I Unwilling 11' No appropriate tin 9 Re11c:1cd to constituent pl3ccbo tin !1 Ready after trial w~s c:omplctc: 1 Wi:lrdraf1111l /ront trial: ~c:idcncal break ofdicr 2 Refused lins 4 indicated only in children with frequent severe attacks, and relapse on reintroduction of the food would be d:teccable only in thos: responding quickly, but the selection was obviously not a bad thing sinc:e those with c:omplic:ated migraine responded as well as those with simple migraine; this also suggests that the existing view that these are all one disease is correct. Dr Cook and Dr JO$Cph (Nov 26, p 1256) fail to understand the principle ofthe oligoantigenic diet (few foods). Any ofthe foods can provoke allergy, so it is not surprising thatsome patients needed a second oligoantigcnic dic:t, and this is nor e\idcnce of failure of c<>miJliano:. Of 1.oursc: sc..ne of the:, syrnptorm <.i1.;iug th<! reintroduction phase may have been fortuitous, but the trial shows that-most were not. They seem to have misphrased their letter; our patients had frequent headaches, nor. one every 6 months. The results were assessed by development of headache, and by preference (ie, any symptom) not by only one related symptom. Since this is the first double-blind controlled trial ofthe food allergy hypothesis of migraine, there ean be no "internationally accepted practic:e". Experimental designs appropri:ne for the study ofdrugs may well be quite different. The suggestion that we should have ruled out deficiencies in cert:iin enzymes prejudges whether such deficiencies arc ca\1$CS or effects of the disease. Since 90% of the children responded to the diet, such differc:nccs are clcarlv unimponant. Those who loo~ for "substantiation" or an ::illergi~ hypothesis by IgE antibody or skin tests will often be disappointed. In answer to Dr Peatfield (Nov 5, p 1082), we would point outthat we arc about to stan a ~tudy of the mcc:hanisms involv.:d, but we doubt whether these will answerthe allcrgyidiosyncrasy questions; both may be true, sometimes together. Like Congdon and Forsythe2 and Moffett et al,3 we are not impressed by the published data on oral tyramine provocation but, if it does work, such a response might be similar to those we observed to physical stimuli in being ~econdary to food allergy. The important point for the patients is that diet an benefit far more of them if it is based on the allergy hypothesis. We agree that a comparison of speed of effect of high and low rartrzzine foods would be interesting. In reply to Dr Stephenson (Nov 26, p 1257), the seizures were typical of partial or generalised epilepsy according ro the international clas.sification. All patients had persistently abnormal EEGs. One had be~n given antiepileptic drugs (by Dr Stephenson himself). The patients who fainted were not included in the epilepsy group. We arc preparing a more detailed account of patients 1.1.ith epilepsy responding to diet. We did not include a question on travel sickness in our questionnaire, but only one on migraine arraclcs provoked by travel. lnari1u1 ofChild Hul1h. London IFC l N I EH J. f:GGl:R J. \\.'11....~o::.r c. M. C.\RTER M. \'(/, TuRNER J. F. SouTHILL 2. Consdon rJ. Fonyth W. M11ra1n< 1n childhood, !!udy o( 300 oh1ldun. >,,,./ /.t.d Cho/J N111"111979, 21: 209-16. ). ,\.\01Tct1 A, Swash M, Scon OF. f.ITcct nf1yraminc on mo:mnc: double blonJ study J 1462 4 69 80