- Email: [email protected]
ORAL CONTRACEPTIVES AND BENIGN LIVER TUMOUR
479 as a fetus will force an improvement in fetal radiography. It would be better to introduce low-dose techniques now, such as those Fisher and I have described.5
Saint Mary’s Hospital, Manchester M13 0JH
J. G.
B. RUSSELL
SIR,—Whilst accepting that criteria for X-ray examination in late pregnancy require careful scrutiny, I feel that the hazards of radiological examination must be carefully weighed against not only the stillbirth-rate and perinatal mortality but also perinatal morbidity, which is very difficult to quantify. In many areas, including the one in which I work, more than 50% of the antenatal patients book after 20 weeks. At this time ultrasound, even if freely available, is of limited value in the assessment of fetal maturity. Beazley and Underhillhave shown that in 22% of patients the estimated date of delivery cannot be predicted by Naegele’s rule for various reasons, including the patient’s own uncertainty about the date of her last menstrual period, prolonged or irregular menstrual cycles, and conception following the use of an oral contraceptive. In such cases the single oblique abdominal film is often of great help in the assessment of fetal
maturity. However, the use of X-ray pelvimetry could be reduced substantially by obstetricians. Joyce et al. have shown that X-ray pelvimetry rarely influences subsequent management in cases of high head at term or in labour. X-ray pelvimetry is of some value in the management of breech presentation; Joyce et al. showed a clear correlation between obstetric conjugate and pelvic capacity. A 3.4 kg baby requires an obstetric conjugate of only 10 cm for a cephalic trial labour, but in the case of a breech presentation an obstetric conjugate of 11.4 cm at 38 weeks and 11.7cm at 40 weeks is necessary for safe successful vaginal delivery. This clear correlation is probably due to the active management of labour, which has eliminated many cases of incoordinate uterine action. Mill Road
Maternity Hospital, Liverpool L6 2AH
J. R. SWINHOE
ORAL CONTRACEPTIVES AND MALIGNANT HEPATOMA
SIR,—Benign hepatic
tumours
in young
women
may be
of oral contraceptives.8-12 Reports of malignant hepatic neoplasia in two young women" 14 prompt this report of a similar instance. A 31-year-old Caucasian female was admitted into hospital in July, 1975, with a 6-week history of abdominal pain and an epigastric mass. Physical examination revealed a visible and related to the
use
palpable epigastric tumour measuring 10 by 12 cm, which was moderately tender and descended with deep inspiration. Isotope scan demonstrated a large defect in the mid-anterior portion of the liver extending into the left lobe. This lesion measured 11 by 12 cm and had an irregular border. Arteriography revealed what appeared to be a solid tumour occupying the entire right lobe of the liver. At laparotomy a football-sized mass was described in the right lobe. Two palpable nodules in the left lobe
were
examined, and frozen section revealed
a
5. Fisher, A. S., Russell, J. G. B. Radiography in Obstetrics. London, 1975. 6. Beazley, J. M., Underhill, R. A. Nursing Times, 1971, iv, 1414. 7. Joyce, D. N., Fjiwa, O., Stevenson, G. W. Br. med. J. 1974, iv, 505. 8. Baum, J. K., Holtz, F., Bookstein, J. J., Klein, E, W. Lancet, 1973, ii, 926. 9. Mays, E. T., Christopherson, W. M., Barrows, G. H. Am. J. clin. Path.
1974, 61, 735. D. R., Lancet, 1974, i, 315. 11.Knapp, W. A., Ruebner, B. H. ibid. 1974, i, 270. 12. Nissen, E. D., Kent, D. R. Obstet. Gynec. 1975, 46, 460. 13. Meyer, P., LiVosi, V. A., Cornog, J. L. Lancet, 1974, ii, 1387. 14. Christopherson, W. M., Mays, E. T., Barrows, G. H. Obstet. Gynec. 1975, 46, 221. 10. Kelso,
A catheter was inserted into the gastroduodenal artery and advanced into the hepatic artery. Histology confirmed the diagnosis of classic hepatocarcinoma. Infusion of 5-floxuridine into the hepatic artery produced a partial response, with reduction in tumour size documented by ultrasound and isotope scans. Throughout the 11-year period immediately before diagnosis this patient had been using oral contraceptives (5 years on norethisterone, 1 mg plus mestranol 0.08 mg, and 6 years on norethisterone, 2 mg plus mestranol 0.1 mg). Although malignant hepatomas occur in relatively young woman, they are rare under the age of 40, with a peak incidence in the 60s.’ The recent reports of malignant liver
malignant hepatoma.
tumour
in
taking oral contraceptives, along with this relationship that may be more than fortuitous.
women
case, suggest
a
San Francisco Hematology-Oncology Associates, San Francisco, California 94115, U.S.A.
ALAN B. GLASSBERG ERNEST H. ROSENBAUM
ORAL CONTRACEPTIVES AND BENIGN LIVER TUMOUR
SIR,—So far, 47 cases of benign liver tumour associated with oral contraceptives have been reported.16 17The tumour has been variously termed benign hepatoma;a hamartoma’9 and focal nodular hyperplasia,2O Malignant transformation of the growth was reported in a single case.17 However, no causal link between oral contraceptives and liver tumours has yet been proved, and a central registry for collecting clinical and pathological data has been suggested.21This prompted us to report on
a
further case.
A 34-year-old woman had taken the oral contraceptive ’Bisecurin’ (ethynodiol, ethinyloestradiol) for 5 years. She pre-
sented with general weakness, polydipsia, polyuria, and episodes of hypoglycaemia of 6 mo duration and recent sensitivity of the right hypochondrium to pressure. A mass was palpable at the right lower margin of the liver. Intravenous cholangiography showed that the gallbladder was slightly contracted and indented laterally, and between it and the liver a mass was suspected. At laparotomy a yellowish-grey sharply delineated solid growth with a nodular surface was found beneath the hepatic capsule behind the gallbladder. The rest of the liver surface was smooth. No other abnormality was found in the abdominal cavity. The tumour was removed in toto along with the gallbladder. The growth measured 6 x 5 x5 cm. It was not encapsulated, being covered only over its abdominal surface by the hepatic capsule, and a thin layer of adjacent normal liver tissue was included in the surgical specimen. The cut surface of the growth was delicately lobular. Microscopically, abnormal liver tissue was found; it was divided by connective-tissue septa, but complete encircling of larger groups of liver cells was rarely seen. In the connective tissue there were veins, a few small arterial branches, and many bile ductules, and in places lymphocytes were abundant. The liver cells, arranged in irregular plates, had a light cytoplasm and did not show any nuclear abnormality. Bile ductules or cells appearing to be transitional between ductular epithelium and hepatocytes were also found between liver cells further away from the septa. The incomplete nodules contained haphazardly arranged veins of the size of the central vein or larger. The lesion is best described as a hamartoma. Isolated liver nodules have been described under various
names-adenoma, hepatoma, solitary hyperplastic nodule, 15. Higgson, J.
in Recent Results in Cancer
Research, vol. 26,
p.
16, Berlin,
1970. 16. 17.
S.
Gut, 1975, 16, 753.
Sherlock, Davis, M., Portmann, B., Searle, M., Wright, R., Williams, R. Br. med. J. 1975, iv, 496. 18. Baum, J. K., Holtz, F., Brookstein, J. J., Klein, E. W. Lancet, 1973, ii, 926. 19. O’Sullivan, J. P., Wilding, R. P. Br. med. J. 1974, iv, 7. 20. Mays, T., Christopherson, W. M., Barrows, G. H. Am. J. clin. Path. 1974, 61, 735. 21. British Medical Journal, 1975, iv, 484.
480 focal cirrhosis, focal nodular hyperplasia .22-27 The variable terminology reflects the diversity of the authors’ opinions on the nature of the lesion; but the main gross and microscopical features of all these nodules corresponded with those observed in women who had been on oral contraceptives for several months or years. Benz and Baggenstoss 12 encountered 34 such liver nodules in the necropsy material of the Mayo Clinic over the period 1922-51. It is interesting that the majority of the nodules were small and, not causing any symptoms, remained unnoticed throughout life. Nearly half of them were found in males. Against this, the majority of cases reported since 1951 have been in young women, and the nodules were larger and usually caused symptoms;23 25-27 whether or not these patients had been on the pill was not pursued. These findings support the suggestion that oral contraceptives might stimulate the growth of pre-existing isolated liver nodules, upon which may follow secondary lesions and symptoms. The true nature of the isolated liver nodules needs to be clarified and the nomenclature reviewed before the precise role of oral contraceptives in the development or progression of hepatic tumours can be determined. Department of Pathology Radioisotope Laboratory
ISTVÁN BARTÓK SUZAN GARAS
Department of Surgery, Péterfy Hospital, 1441 Budapest, P.O. Box
76,
LÁSZLÓ SZABÓ
Hungary
ARMS AND THE BRONCHI
SIR,-We agree28 with you (Feb. 7, p. 287) about the need for a continued search for biochemical mediators in exerciseinduced asthma, but we feel that the emphasis placed on differences between different types of exercise might be misleading. Is running really more likely to provoke asthma than cycling? You indicate, and we have said it ourselves,29 that in comparisons of this type the important measure of work to control and report is total oxygen consumption. We are told that the rate of exercise is unimportant, but examination of the literature purporting to show a greater bronchial response to running reveals that it is this, and not total oxygen consumption, which has been reported.3O-33 When we measured total oxygen consumption 29 we found no difference in the bronchial response to treadmill-running and ergometer-pedalling. You suggest that the limit of bronchial response to work is reached at a total oxygen consumption of approximately 200 ml/kg body-weight, and imply that this is more or less independent of the type of subject and form of exercise. We find the evidence used in support of this figure" to be unsatisfactory. Surely there must be considerable biological variation in what represents "maximal stimulation". Our view is that there is no substitute for actual measurement of total oxygen consumption, and until more such studies are reported the relative effects of different types of exercise in asthma must remain un7 certain. We might add that we find the cycle ergometer per22. 23. 24. 25.
Benz, E. J., Baggenstoss, A. H. Cancer, 1953, 6, 743. Begg, C. F., Berry, W. H. Am. J. clin. Path. 1953, 23, 447. Edmondson, H. A. Am. J. Dis. Child. 1956, 91, 168. Palubinskas, A. J., Baldwin, J., McCormack, K. R. Radiology, 1967, 89, 444.
26. 27. 28.
Whelan, T. J., Baugh, J. H., Chandor, S. Ann. Surg. 1973, 177, 150. McLoughlin, M. J., Colapinto, R. F., Gilday, D. L., Hobbs, B. B., Korobkin, M. T., McDonald, P., Phillips, J. Radiology, 1973, 107, 257. Seaton, A., Davies, G., Gaziano, D., Hughes, R. O. Br. med. J. 1969, iii, 556.
29. 30. 31. 32. 33.
Miller, G. J., Davies, B. H., Cole, T. J., Seaton, A. Thorax, 1975, 30, 306. Fitch, K. D., Morton, A. R. Br. med. J. 1971, iv. 577. Anderson, S. D., Connolly, N. M., Godfrey, S. Thorax, 1971, 26, 396. Silverman, M., Anderson, S. D. Archs Dis. Childh. 1972, 47, 882. Anderson, S. D., Silverman, M., König, P., Godfrey, S. Br. J. Dis. Chest, 1975, 69, 1.
fectly satisfactory for the study of exercise-induced asthma in the clinical laboratory. .
Medical Research Council Pneumoconiosis Unit,
Llandough Hospital, Penarth, South Wales
G. J. MILLER
Sully Hospital, Sully, Glamorgan
A. SEATON B. H. DAVIES
NOCTURNAL WHEEZE AND MITE SENSITIVITY
SIR,—Dr Burr and his colleagues (Feb. 14, p. 333) describe Dermatophagoides pteronyssinus as causing nocturnal asthma in sensitive subjects. Nocturnal wheezing is a very common complaint in asthmatics, whether their asthma is extrinsic or intrinsic. A questionnaire completed by 40 of our asthmatic patients showed that 75% of the intrinsics were troubled with nocturnal wheeze compared with 93% of the extrinsic patients; the difference is rather small if allergy to the mite is a major cause of nocturnal wheezing. Asthmatics also seem to complain of nocturnal wheezing during exacerbation due to seasonal pollen asthma and when psychological factors (e.g., examinations) are operative. If type-I allergy is involved it is strange that the patients often wake in the early hours of the morning, i.e., after several hours of exposure. More than 80% of extrinsic asthmatics demonstrate positive skin tests to the house-dust mite.’ It is difficult to prove that sensitivity to the mite is a major cause of nocturnal wheeze, so anti-mite measure may not be as successful as anticipated. Chest
Clinic,
G. J. ARCHER S. K. U. MALIK
Stepping Hill Hospital, Stockport SK2 7UE
SIR The asthmatic patients studied by Dr Burr and his
colleagues had positive skin tests to D. pteronyssinus, but there is no indication that their symptoms were precipitated or exacerbated by dust contact. Many adults with asthma are atopic and may have positive skin tests to D. pteronyssimus and,other common allergens. A positive skin test does not necessarily mean that the allergen is relevant to the patient’s symptoms. I hope the conclusions of Dr Burr and his colleagues will not dissuade physicians from advising measures to reduce the mite population in the homes of patients whose symptoms are clearly related to house-dust exposure. Department of General Medicine, Frenchay Hospital, Bristol BS16 1LE
R. J. WHITE
SIR,—I have studied 200 patients at this allergy clinic and have had many patients with mite-sensitive asthma who have been given inadequate advice from other allergy clinics about reduction of exposure to house-dust mite. Many of these patients had failed to benefit because the advice given still allowed exposure to this mite. There is a very significant aerosol from the base of the bed which should also be covered with ’Polythene’, and, in our experience, the house-dust-mite antigen cannot be removed from pillows containing any potential air space. I advise the patient to cover the mattress and base wi6 polythene; the pillow should also be covered with polythene, and a pillow-slip with a towel under it may be used for greater comfort. The blankets should be washed every two or three months, and any quilt is discarded unless it is of very light material and easily washed. It is also advisable (especially with children) to treat any other bed in the room. 1.
Hendrick, II.
D.
J., Davies,
R.
J., D’Souza, M. F., Pepys, J. Thorax, 1975, 30,
Saint Mary’s Hospital, Manchester M13 0JH
J. G.
B. RUSSELL
SIR,—Whilst accepting that criteria for X-ray examination in late pregnancy require careful scrutiny, I feel that the hazards of radiological examination must be carefully weighed against not only the stillbirth-rate and perinatal mortality but also perinatal morbidity, which is very difficult to quantify. In many areas, including the one in which I work, more than 50% of the antenatal patients book after 20 weeks. At this time ultrasound, even if freely available, is of limited value in the assessment of fetal maturity. Beazley and Underhillhave shown that in 22% of patients the estimated date of delivery cannot be predicted by Naegele’s rule for various reasons, including the patient’s own uncertainty about the date of her last menstrual period, prolonged or irregular menstrual cycles, and conception following the use of an oral contraceptive. In such cases the single oblique abdominal film is often of great help in the assessment of fetal
maturity. However, the use of X-ray pelvimetry could be reduced substantially by obstetricians. Joyce et al. have shown that X-ray pelvimetry rarely influences subsequent management in cases of high head at term or in labour. X-ray pelvimetry is of some value in the management of breech presentation; Joyce et al. showed a clear correlation between obstetric conjugate and pelvic capacity. A 3.4 kg baby requires an obstetric conjugate of only 10 cm for a cephalic trial labour, but in the case of a breech presentation an obstetric conjugate of 11.4 cm at 38 weeks and 11.7cm at 40 weeks is necessary for safe successful vaginal delivery. This clear correlation is probably due to the active management of labour, which has eliminated many cases of incoordinate uterine action. Mill Road
Maternity Hospital, Liverpool L6 2AH
J. R. SWINHOE
ORAL CONTRACEPTIVES AND MALIGNANT HEPATOMA
SIR,—Benign hepatic
tumours
in young
women
may be
of oral contraceptives.8-12 Reports of malignant hepatic neoplasia in two young women" 14 prompt this report of a similar instance. A 31-year-old Caucasian female was admitted into hospital in July, 1975, with a 6-week history of abdominal pain and an epigastric mass. Physical examination revealed a visible and related to the
use
palpable epigastric tumour measuring 10 by 12 cm, which was moderately tender and descended with deep inspiration. Isotope scan demonstrated a large defect in the mid-anterior portion of the liver extending into the left lobe. This lesion measured 11 by 12 cm and had an irregular border. Arteriography revealed what appeared to be a solid tumour occupying the entire right lobe of the liver. At laparotomy a football-sized mass was described in the right lobe. Two palpable nodules in the left lobe
were
examined, and frozen section revealed
a
5. Fisher, A. S., Russell, J. G. B. Radiography in Obstetrics. London, 1975. 6. Beazley, J. M., Underhill, R. A. Nursing Times, 1971, iv, 1414. 7. Joyce, D. N., Fjiwa, O., Stevenson, G. W. Br. med. J. 1974, iv, 505. 8. Baum, J. K., Holtz, F., Bookstein, J. J., Klein, E, W. Lancet, 1973, ii, 926. 9. Mays, E. T., Christopherson, W. M., Barrows, G. H. Am. J. clin. Path.
1974, 61, 735. D. R., Lancet, 1974, i, 315. 11.Knapp, W. A., Ruebner, B. H. ibid. 1974, i, 270. 12. Nissen, E. D., Kent, D. R. Obstet. Gynec. 1975, 46, 460. 13. Meyer, P., LiVosi, V. A., Cornog, J. L. Lancet, 1974, ii, 1387. 14. Christopherson, W. M., Mays, E. T., Barrows, G. H. Obstet. Gynec. 1975, 46, 221. 10. Kelso,
A catheter was inserted into the gastroduodenal artery and advanced into the hepatic artery. Histology confirmed the diagnosis of classic hepatocarcinoma. Infusion of 5-floxuridine into the hepatic artery produced a partial response, with reduction in tumour size documented by ultrasound and isotope scans. Throughout the 11-year period immediately before diagnosis this patient had been using oral contraceptives (5 years on norethisterone, 1 mg plus mestranol 0.08 mg, and 6 years on norethisterone, 2 mg plus mestranol 0.1 mg). Although malignant hepatomas occur in relatively young woman, they are rare under the age of 40, with a peak incidence in the 60s.’ The recent reports of malignant liver
malignant hepatoma.
tumour
in
taking oral contraceptives, along with this relationship that may be more than fortuitous.
women
case, suggest
a
San Francisco Hematology-Oncology Associates, San Francisco, California 94115, U.S.A.
ALAN B. GLASSBERG ERNEST H. ROSENBAUM
ORAL CONTRACEPTIVES AND BENIGN LIVER TUMOUR
SIR,—So far, 47 cases of benign liver tumour associated with oral contraceptives have been reported.16 17The tumour has been variously termed benign hepatoma;a hamartoma’9 and focal nodular hyperplasia,2O Malignant transformation of the growth was reported in a single case.17 However, no causal link between oral contraceptives and liver tumours has yet been proved, and a central registry for collecting clinical and pathological data has been suggested.21This prompted us to report on
a
further case.
A 34-year-old woman had taken the oral contraceptive ’Bisecurin’ (ethynodiol, ethinyloestradiol) for 5 years. She pre-
sented with general weakness, polydipsia, polyuria, and episodes of hypoglycaemia of 6 mo duration and recent sensitivity of the right hypochondrium to pressure. A mass was palpable at the right lower margin of the liver. Intravenous cholangiography showed that the gallbladder was slightly contracted and indented laterally, and between it and the liver a mass was suspected. At laparotomy a yellowish-grey sharply delineated solid growth with a nodular surface was found beneath the hepatic capsule behind the gallbladder. The rest of the liver surface was smooth. No other abnormality was found in the abdominal cavity. The tumour was removed in toto along with the gallbladder. The growth measured 6 x 5 x5 cm. It was not encapsulated, being covered only over its abdominal surface by the hepatic capsule, and a thin layer of adjacent normal liver tissue was included in the surgical specimen. The cut surface of the growth was delicately lobular. Microscopically, abnormal liver tissue was found; it was divided by connective-tissue septa, but complete encircling of larger groups of liver cells was rarely seen. In the connective tissue there were veins, a few small arterial branches, and many bile ductules, and in places lymphocytes were abundant. The liver cells, arranged in irregular plates, had a light cytoplasm and did not show any nuclear abnormality. Bile ductules or cells appearing to be transitional between ductular epithelium and hepatocytes were also found between liver cells further away from the septa. The incomplete nodules contained haphazardly arranged veins of the size of the central vein or larger. The lesion is best described as a hamartoma. Isolated liver nodules have been described under various
names-adenoma, hepatoma, solitary hyperplastic nodule, 15. Higgson, J.
in Recent Results in Cancer
Research, vol. 26,
p.
16, Berlin,
1970. 16. 17.
S.
Gut, 1975, 16, 753.
Sherlock, Davis, M., Portmann, B., Searle, M., Wright, R., Williams, R. Br. med. J. 1975, iv, 496. 18. Baum, J. K., Holtz, F., Brookstein, J. J., Klein, E. W. Lancet, 1973, ii, 926. 19. O’Sullivan, J. P., Wilding, R. P. Br. med. J. 1974, iv, 7. 20. Mays, T., Christopherson, W. M., Barrows, G. H. Am. J. clin. Path. 1974, 61, 735. 21. British Medical Journal, 1975, iv, 484.
480 focal cirrhosis, focal nodular hyperplasia .22-27 The variable terminology reflects the diversity of the authors’ opinions on the nature of the lesion; but the main gross and microscopical features of all these nodules corresponded with those observed in women who had been on oral contraceptives for several months or years. Benz and Baggenstoss 12 encountered 34 such liver nodules in the necropsy material of the Mayo Clinic over the period 1922-51. It is interesting that the majority of the nodules were small and, not causing any symptoms, remained unnoticed throughout life. Nearly half of them were found in males. Against this, the majority of cases reported since 1951 have been in young women, and the nodules were larger and usually caused symptoms;23 25-27 whether or not these patients had been on the pill was not pursued. These findings support the suggestion that oral contraceptives might stimulate the growth of pre-existing isolated liver nodules, upon which may follow secondary lesions and symptoms. The true nature of the isolated liver nodules needs to be clarified and the nomenclature reviewed before the precise role of oral contraceptives in the development or progression of hepatic tumours can be determined. Department of Pathology Radioisotope Laboratory
ISTVÁN BARTÓK SUZAN GARAS
Department of Surgery, Péterfy Hospital, 1441 Budapest, P.O. Box
76,
LÁSZLÓ SZABÓ
Hungary
ARMS AND THE BRONCHI
SIR,-We agree28 with you (Feb. 7, p. 287) about the need for a continued search for biochemical mediators in exerciseinduced asthma, but we feel that the emphasis placed on differences between different types of exercise might be misleading. Is running really more likely to provoke asthma than cycling? You indicate, and we have said it ourselves,29 that in comparisons of this type the important measure of work to control and report is total oxygen consumption. We are told that the rate of exercise is unimportant, but examination of the literature purporting to show a greater bronchial response to running reveals that it is this, and not total oxygen consumption, which has been reported.3O-33 When we measured total oxygen consumption 29 we found no difference in the bronchial response to treadmill-running and ergometer-pedalling. You suggest that the limit of bronchial response to work is reached at a total oxygen consumption of approximately 200 ml/kg body-weight, and imply that this is more or less independent of the type of subject and form of exercise. We find the evidence used in support of this figure" to be unsatisfactory. Surely there must be considerable biological variation in what represents "maximal stimulation". Our view is that there is no substitute for actual measurement of total oxygen consumption, and until more such studies are reported the relative effects of different types of exercise in asthma must remain un7 certain. We might add that we find the cycle ergometer per22. 23. 24. 25.
Benz, E. J., Baggenstoss, A. H. Cancer, 1953, 6, 743. Begg, C. F., Berry, W. H. Am. J. clin. Path. 1953, 23, 447. Edmondson, H. A. Am. J. Dis. Child. 1956, 91, 168. Palubinskas, A. J., Baldwin, J., McCormack, K. R. Radiology, 1967, 89, 444.
26. 27. 28.
Whelan, T. J., Baugh, J. H., Chandor, S. Ann. Surg. 1973, 177, 150. McLoughlin, M. J., Colapinto, R. F., Gilday, D. L., Hobbs, B. B., Korobkin, M. T., McDonald, P., Phillips, J. Radiology, 1973, 107, 257. Seaton, A., Davies, G., Gaziano, D., Hughes, R. O. Br. med. J. 1969, iii, 556.
29. 30. 31. 32. 33.
Miller, G. J., Davies, B. H., Cole, T. J., Seaton, A. Thorax, 1975, 30, 306. Fitch, K. D., Morton, A. R. Br. med. J. 1971, iv. 577. Anderson, S. D., Connolly, N. M., Godfrey, S. Thorax, 1971, 26, 396. Silverman, M., Anderson, S. D. Archs Dis. Childh. 1972, 47, 882. Anderson, S. D., Silverman, M., König, P., Godfrey, S. Br. J. Dis. Chest, 1975, 69, 1.
fectly satisfactory for the study of exercise-induced asthma in the clinical laboratory. .
Medical Research Council Pneumoconiosis Unit,
Llandough Hospital, Penarth, South Wales
G. J. MILLER
Sully Hospital, Sully, Glamorgan
A. SEATON B. H. DAVIES
NOCTURNAL WHEEZE AND MITE SENSITIVITY
SIR,—Dr Burr and his colleagues (Feb. 14, p. 333) describe Dermatophagoides pteronyssinus as causing nocturnal asthma in sensitive subjects. Nocturnal wheezing is a very common complaint in asthmatics, whether their asthma is extrinsic or intrinsic. A questionnaire completed by 40 of our asthmatic patients showed that 75% of the intrinsics were troubled with nocturnal wheeze compared with 93% of the extrinsic patients; the difference is rather small if allergy to the mite is a major cause of nocturnal wheezing. Asthmatics also seem to complain of nocturnal wheezing during exacerbation due to seasonal pollen asthma and when psychological factors (e.g., examinations) are operative. If type-I allergy is involved it is strange that the patients often wake in the early hours of the morning, i.e., after several hours of exposure. More than 80% of extrinsic asthmatics demonstrate positive skin tests to the house-dust mite.’ It is difficult to prove that sensitivity to the mite is a major cause of nocturnal wheeze, so anti-mite measure may not be as successful as anticipated. Chest
Clinic,
G. J. ARCHER S. K. U. MALIK
Stepping Hill Hospital, Stockport SK2 7UE
SIR The asthmatic patients studied by Dr Burr and his
colleagues had positive skin tests to D. pteronyssinus, but there is no indication that their symptoms were precipitated or exacerbated by dust contact. Many adults with asthma are atopic and may have positive skin tests to D. pteronyssimus and,other common allergens. A positive skin test does not necessarily mean that the allergen is relevant to the patient’s symptoms. I hope the conclusions of Dr Burr and his colleagues will not dissuade physicians from advising measures to reduce the mite population in the homes of patients whose symptoms are clearly related to house-dust exposure. Department of General Medicine, Frenchay Hospital, Bristol BS16 1LE
R. J. WHITE
SIR,—I have studied 200 patients at this allergy clinic and have had many patients with mite-sensitive asthma who have been given inadequate advice from other allergy clinics about reduction of exposure to house-dust mite. Many of these patients had failed to benefit because the advice given still allowed exposure to this mite. There is a very significant aerosol from the base of the bed which should also be covered with ’Polythene’, and, in our experience, the house-dust-mite antigen cannot be removed from pillows containing any potential air space. I advise the patient to cover the mattress and base wi6 polythene; the pillow should also be covered with polythene, and a pillow-slip with a towel under it may be used for greater comfort. The blankets should be washed every two or three months, and any quilt is discarded unless it is of very light material and easily washed. It is also advisable (especially with children) to treat any other bed in the room. 1.
Hendrick, II.
D.
J., Davies,
R.
J., D’Souza, M. F., Pepys, J. Thorax, 1975, 30,