dietary prophylaxis of allergy

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- can provide any satisfactory check on faecal-fat deter-minations. The Birmingham workers describe cases ofnon-tropical sprue in which the daily faecal-fat excretionexceeded that ingested (6 g.) for several days after asingle loading dose of extra fat. The excess over intakewas, however, small, so errors in technique cannot

entirely be ruled out-which underlines the need foraccurate check on the fat analysis of diet and faeces.To substantiate the hypothesis that the endogenous

fat might originate from chyle secreted into the lumenafter blockage of the lymphatics, Cooke et al. examinedthe fat excretion from isolated loops of intestine of dogsbefore and after ligation of the thoracic duct. Theyfound a distinct increase in the total lipids, accountedfor by increased excretion of neutral fat. It is still

uncertain, however, whether blockage of the lymphaticsin the human adult-for example, in Hodgkin’s disease,carcinoma, and reticulosarcoma-ever causes steator-rhoea without simultaneous involvement of the intestinalwall. Jimenez Diaz and his colleagues 11 have shown thatlymphatic blockage can bring about temporary increaseof fsecal-fat excretion, and in some of their patients withsteatorrhoea the evidence suggested that excretion of

endogenous fat was increased. Probably such a mechanismoperates, if at all, only in certain types of idiopathicsteatorrhoea.We may learn more about the origins of faecal fat from

administration of individual fats, or of chemically similarfats, and analysis of the types of fat then excreted, andfrom further work on the role of the intestinal flora.

12. Pepys, J. Postgrad. med. J. 1953, 29, 351, 517, 564.13. von Pirquet, C. Münch. med. Wschr. 1906, 30, 1457.14. Williams, D. A. First International Congress of Allergy, Zürich,

1951.15. Walzer, M. J. Allergy. 1931, 2, 399.16. Bernton, H. S. Ann. Allergy, 1949, 7, 13.17. Rosenau, M. J. Preventive Medicine and Hygiene. New York,

1935.18. Donnally, H. H. J. Immunol. 1930, 19, 15.19. Grulee, C. G., Sanford, H. N. J. Pediat. 1936, 9, 233.

DIETARY PROPHYLAXIS OF ALLERGY" ALLERGY," as Pepys 12 points out, is a sorely misused

word. As used clinically it should imply a hypersensitivestate acquired through exposure to a particularallergen, re-exposure bringing to light what von

Pirquet 13 termed " an altered capacity to react." Thisaltered capacity manifests itself clinically in any ofseveral ways ; and each of these manifestations may bemodified or overlaid by emotional, infective, endocrine,and other factors. Some 10% of the population of Britainare believed to suffer from allergic disorders, which havebeen found to account for about 5% of the final diagnosesin patients admitted to hospitals.14 In England andWales deaths from asthma alone averaged 2915 in eachof the years 1938-48.

In treatment the anti-histamine drugs and cortisoneand corticotrophin are proving useful ; but these do notproduce a lasting modification of the allergic state.

Perhaps the best hope of progress lies in prevention, andnotably in- the protection of infants from potentialallergens. Control of the mother’s diet during pregnancy,to prevent sensitisation of the foetus, has been proposed ;but this has not yet been proved of value. The newborninfant is particularly susceptible to ingested allergens :its gastro-intestinal tract is " almost like a sieve

according to Walzer,15 who found that passive transfertests became positive while the infant was still feedingfrom the bottle containing the allergen. Furthermoreintestinal absorption of unaltered protein has beendemonstrated ; and this may be important in the produc-tion of sensitisation. Yet there seems to be no conclusiveevidence for the transmission of allergens through breast-milk 16—a finding which is the more surprising becauseapparently both drugs 17 and food-proteins 18 may beexcreted in the milk. At all events breast-milk is muchless likely than cow’s milk to lead to allergy ; Gruleeand Sanford,19 for example, have shown that infantile

eczema is seven times commoner in infants fed on cow’smilk than in those who are wholly breast-fed. Glaserand Johnstone 20 have devised a diet, consisting of a" milk " prepared from soya-beans with meat base andmineral supplements, to delay the introduction of cow’smilk into the diet. Of 96 infants, 3 were exclusivelybreast-fed. The remaining 93 were given the soya-beandiet, with cow’s milk added before the age of threemonths in 24 cases, and between the ages of three andnine months in altogether 67 cases. Follow-up, for

periods ranging from seven months to ten years (themajority were observed for more than two years), showedallergic disorders in 15% of these 96 children, comparedwith 64% of 70 sibling controls and 52% of an unrelatedgroup of 175.The commonest early manifestation of allergy is

infantile eczema ; and this may be followed by respira-tory allergic disorders-in 34-56% of cases according toPurdy,21 andin up to 80% of cases according toMacKinneyand Glaser.22 These are unwelcome disturbances; butalthough Glaser and Johnstone found that 85% of infantssubsisted well enough on their soya-bean diet, mostmothers are unlikely to displace cow’s milk in its favour.

20. Glaser, J., Johnstone, D. E. Ann. Allergy, 1952, 10, 433 ; J.Amer. med. Ass. 1953, 153, 620.

21. Purdy, M. J. Brit. med, J. 1953, i, 1366.22. MacKinney, L. G., Glaser, J. Ann. Allergy (in the press).23. Griffiths, J. A. Quart. J. Med. 1953, 22, 405.24. Laurence, D. R., Stacey, R. S. Brit. J. Pharmacol. 1952, 7, 255.

DIABETES AND CONTROLLED HYPOTENSION

OPERATION under anaesthesia, is little more risky forthe patient with well-controlled diabetes than for anyother ; but Griffiths 23 has described 2 cases of severehypoglycaemia in diabetics when the technique of con-trolled hypotension with hexamethonium bromide wasused. Prompted by this experience, he investigatednon-diabetic and diabetic patients under standardconditions of anaesthesia. In non-diabetics duringsuperficial operations the blood-sugar level remainedconstant throughout, while during upper abdominalsection there was a rise in the level which was statisticallysignificant though clinically unimportant. When hexa-methonium was administered to non-diabetics for super-ficial operations the blood-sugar was decreased ; in mostcases it remained stable at the lower level, but in 2 severe

cases hypoglycæmia was precipitated. 3 patients withcontrolled diabetes undergoing superficial operations hada stable blood-sugar with the standard anaesthetic tech-nique, but a 4th had a precipitous decline in blood-sugarafter the injection of hexamethonium.

Griffiths has shown that the anaesthetic sequencethiopentone, gallamine, nitrous-oxide/oxygen, and pethi-dine, with full oxygenation throughout, has no effect onblood-sugar in either non-diabetic or diabetic patients,but that major operations may be associated with anincrease, presumably because of adrenaline release throughautonomic stimuli from the operation site. Laurence andStacey 24 have shown that, in unanaesthetised man,whether diabetic or non-diabetic, intravenous hexa-methonium potentiates the action of parenteral insulinand masks many of the signs of hypoglycæmia. Griffithshas now confirmed these findings in the anæsthetisedpatient, and he emphasises that progressive tachycardiais the only constant sign of -even severe hypoglycsemiaunder anaesthesia. He concludes that controlled hypo-tension with hexamethonium bromide is contra-indicatedfor diabetic patients.

THE INDEX and title-page to Vol. II, 1953, which wascompleted with THE LANCET of Dec. 26, is publishedwith our present issue. A copy will be sent gratis tosubscribers on receipt of a postcard addressed to theManager of THE LANCET, 7, Adam Street, Adelphi, W.C.2.Subscribers who have not already indicated their desireto receive indexes regularly as published should do so now.