Table 1

Characteristics and laboratory examination of patients

	Patient 1 Asthma induced by buckwheat	Patient 2 Asthma induced by wheat
Age, sex	54, man	42, man
Occupation	Factory making buckwheat noodles	Baker
History of the work	36 y, since age 18	16 y, since age 26
Habits	Non-smoker and social drinker	Non-smoker and never drinker
Peripheral eosinophils (%)	23	0
Total IgE (IU/ml)	176	458
FEV₁ (% predicted)	1.31 (49%)	3.89 (69.5%)
PaCO₂, PaO₂ (mm Hg)	42, 60	40, 93
PC20^1-150 (mg/ml)	0.625	0.128
Chestx ray film	Normal	Normal
Prick test^1-151 (mm)		Buckwheat flour extract	Wheat flour extract (10⁻³ g/ml)
		10⁻³ g/ml: 4 × 4 / 28 × 25	A–F: all positive
		10⁻⁴ g/ml : negative	A–F: all positive
Skin test (mm)		Buckwheat flour extract:	Wheat flour extract: ^(threshold)
		10⁻⁶ g/ml: 12 × 10 / 40 × 33	A: 10⁻⁶ g/ml, B: 10⁻⁵ g/ml, C∼F: 10⁻⁴ g/ml
		10⁻⁷ g/ml: negative	A: 10⁻⁶ g/ml, B: 10⁻⁵ g/ml, C∼F: 10⁻⁴ g/ml
Prausnitz-Küstner reaction	Not done	Positive for wheat flour extracts A, B, C, D, E, F
IgE-RAST^‡		Buckwheat flour: class 3	Wheat flour : class 5
IgE-RAST^‡		Other 30 antigens: all negative	Other 18 antigens: all negative
Bronchoprovocation test^§		Buckwheat flour extract (10⁻³ g/ml)	Wheat flour extract (A: 10⁻² g/ml)
		IAR: negative	IAR: 23% fall in FEV₁
		LAR: 32% fall in FEV₁ 7 h later	LAR: 33% fall in FEV₁ 7 h later
Environmental provocation test^¶		Work for 30 minutes	Work for 15 minutes
		IAR: negative	IAR: 39% fall in PEFR
		LAR: 44% fall in PEFR 9 h later	LAR: 36% in PEFR 7 h later

↵1-150 Non-specific methacholine bronchial provocation test.
↵1-151 Results of the skin prick test were expressed as wheal / flare (mm). In Patient 2, antigens were prepared using six components (component A–F) of the wheat flour that were usually used by the patient (see text).
RAST: radioallergosorbent test; IAR=immediate asthmatic reaction; LAR=late asthmatic reaction; PEFR=peak expiratory flow rate.