Excretion of urinary histamine and N-tele methylhistamine in patients with gastrointestinal food allergy compared to non-allergic controls during an unrestricted diet and a hypoallergenic diet.

BACKGROUND: Patients with gastrointestinal food allergy are characterised by increased production of mast cell derived mediators upon allergen contact and present often with unspecific symptoms. The aim of this study was to evaluate urinary histamine and methylhistamine excretion in patients with food allergy and to compare their values with food-tolerant controls. METHODS: In a retrospective case control study the urinary excretion parameters were analysed from 56 patients (40.9, 19 - 58 years) in whom later food challenge tests confirmed food allergy. During their diagnostic work-up urine was collected during a 12-h period under an unrestricted diet with staple foods and a hypoallergenic potato-rice-diet (each 2 days). Healthy controls underwent the same diet types to define normal excretion parameters. Urinary histamine and n-methylhistamine were determined by ELISA or tandem mass spectrometry, respectively, and were expressed as median (25 - 75% range, µg/mmol creatinine x m(2)BSA). RESULTS: During unrestricted diet urinary histamine was significantly higher in gastrointestinal food allergy than healthy controls (1.42, 0.9 - 2.7 vs 0.87, 0.4 - 1.3; p < 0.0001), while the difference between both groups became marginal during potato-rice diet (1.30, 0.7 - 2.1 vs 1.05, 0.5 - 1.5; p = 0.02). N-methylhistamine was found to be significantly elevated in gastrointestinal food allergy both during unrestricted diet (7.1, 5.0 - 11.2) and potato-rice diet (5.7, 3.7 - 8.7) compared to controls (p < 0.0001). Interestingly, urinary methylhistamine excretion (p < 0.004) and clinical symptom score (p < 0.02) fell significantly when the diet was switched from unrestricted to hypoallergenic food, but was not correlated with symptom scores. CONCLUSIONS: In gastrointestinal food allergy significantly higher levels of urine histamine and methylhistamine excretion were found under unrestricted diet, reflecting an increased secretion of histamine due to offending foods. Measurement of urinary n-methylhistamine levels may help to find out patients with increased histamine production and/or food-allergen induced clinical symptoms, respectively.

[Pyrethroid exposure following indoor treatments with a dog flea powder]. / Pyrethroidbelastung durch Parasitenprophylaxe beim Hund.

UNLABELLED: Pyrethroid exposure following indoor treatments with a dog flea powder. HISTORY: A 42 year old woman reported hair loss, gastrointestinal and non-specific symptoms. The patient has lived in a council flat and kept a dog who had been regularly treated with pyrethroid containing flea powder. INVESTIGATIONS: The biological monitoring of pyrethroid meta-bolites in urine was performed using gas chromatography-mass spectrometry. The values at admission and follow-up after 4 weeks were highly elevated. Inspection of the flat revealed a humid and cramped dwelling. TREATMENT: We recommended redevelopment and cleaning of the dwelling and the avoidance of ectoparasiticide use. CONCLUSION: To our knowledge this is the first documented case of high indoor pyrethroid exposure following the use of ectoparasiticides with domestic animals. Pyrethroids can cause neurotoxic symptoms and skin irritation. There are few data concerning chronic effects. The causal connection between pyrethroid exposure and symptoms remains unclear and poses a great problem in environmental medicine.

Effect of metoclopramide therapy on arginine vasopressin excretion and renal water handling in premature infants.

The role of endogenous dopamine (DA) in regulating arginine vasopressin (AVP) release and renal water excretion was studied in 10 premature infants with a mean birth weight of 1,341 g (range 1,150-1,660 g) and a mean gestational age of 30.2 weeks (28-33 weeks), who were given metoclopramide (MTC), a specific DA antagonist. It was demonstrated that in response to MTC urine flow rate increased significantly from a basal value of 0.90 +/- 0.07 to 1.27 +/- 0.09 ml/min/1.73 m2 (mean +/- SE; p less than 0.01), urinary sodium excretion from 6.10 +/- 1.47 to 11.7 +/- 2.24 microEq/min/1.73 m2 (p less than 0.025) and osmolar clearance from 0.38 +/- 0.044 to 0.600 +/- 0.075 ml/min/1.73 m2 (p less than 0.01). MTC administration did not cause any alterations in free water clearance, whereas urinary AVP excretion fell significantly from 49.38 +/- 10.13 to 32.66 +/- 6.53 ng/min/1.73 m2 (p less than 0.05) after MTC. It is concluded that, contrary to adults, in low birth weight premature infants endogenous DA is enhancing rather than inhibiting AVP release and the MTC-induced water diuresis is independent of the fall of AVP since free water clearance remained unaltered after MTC.