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Biomedical subjects

P Hauk

Publications and source records attributed to P Hauk.

7 recordsLinked to original sources

In vivo histamine release during the first minutes after deliberate sting challenges correlates with the severity of allergic symptoms.

In this study, deliberate sting challenge was investigated as a method for estimating the severity of anaphylactic reactions in bee venom-sensitized subjects. Twenty-one patients with previous anaphylactic reactions to field bee sting were subjected to a deliberate sting challenge (n = 32). To document anaphylactic reactions, plasma histamine levels were measured before, and then 1 and 2 min after, bee sting challenge. Eleven patients were re-challenged after 3-5 weeks. On 18 occasions, sting challenges caused no systemic reactions, in seven cases reactions were mild, in five moderate and in two severe. In all children showing systemic reactions, significant increases of plasma histamine were measured after 2 min. The results correlated significantly with clinical scores but not with skin prick test or with specific immunoglobulin E (IgE) and immunoglobulin G (IgG) antibodies against bee venom. In patients developing local reactions only, no increase of plasma histamine was detected. The relative amount of released histamine correlated significantly with the severity of clinical symptoms. Significant histamine release occured during the first 2 min after sting challenge in children with subsequent systemic reactions and the severity of these subsequent anaphylactic reactions correlated with plasma histamine concentrations. The measurement of plasma histamine levels in the first minutes after challenge test may therefore be used as an objective marker of a potential systemic reaction.

Adolescent↗

The role of superantigens in human diseases: therapeutic implications for the treatment of skin diseases.

Although it is well established that immune mechanisms contribute to the pathogenesis of chronic inflammatory skin diseases such as atopic dermatitis (AD) and psoriasis, the actual events that trigger the immunological pathways resulting in these skin diseases are not well understood. Colonization and infection with Staphylococcus aureus and streptococci has been reported to exacerbate AD and psoriasis. Recent studies demonstrating that bacterial toxins can act as superantigens provide mechanism(s) by which S. aureus and streptococci could mediate an inflammatory skin lesion that consists predominantly of activated T-cells and monocytes. This review will explore the diverse mechanisms by which bacterial superantigens can induce skin inflammation following systemic or local infection. These observations provide a new direction for the development of novel approaches for the treatment of skin inflammation.

Anti-Bacterial Agents↗

Subsequent insect stings in children with hypersensitivity to Hymenoptera.

To investigate the risk of life-threatening reactions to future stings, we sequentially challenged 113 children (aged 2 to 17 years) allergic to insect stings with a sting by the relevant insect. The time interval between the challenges varied from 2 to 6 weeks. The history of the index stings was a large local reaction (LR) in 16% and a systemic reaction (SR) in 84% of the test subjects. On the first challenge, 76% had a normal LR, 11% a large LR, and 13% an SR. On the second challenge, 78% of the children had a normal LR, 5% a large LR, and 17% an SR. Thirty-nine of the untreated children were exposed to a field sting during the subsequent 3-year follow-up period. In comparison with other diagnostic evaluations such as skin-prick tests, determinations of specific IgE and IgG antibodies, and single-sting exposure, the dual sting challenge scheme appears to be the best predictor of reactions to subsequent stings. It also appears to be helpful in selecting patients with an uncertain sensitization status for venom immunotherapy.

Adolescent↗

Anaphylactic reactions to bee-sting challenges in allergic children are not modified by endogenous catecholamines.

To investigate the role of basal catecholamine levels and the response of the adrenergic system to expected bee stings, plasma catecholamines were measured before and 1 and 2 min after bee-sting challenges. Twenty-one children (aged 4-15 y) with bee-sting allergies were selected for sequential challenges to establish the need for venom immunotherapy. The time interval between the challenges varied from 2 to 6 wk. Epinephrine, norepinephrine, and dopamine plasma levels were measured using a simultaneous single-isotope radioenzymatic assay. On the first challenge, 33% of the children experienced a normal local reaction, 29% a large local reaction, and 38% a systemic reaction. On the second challenge in 18 out of 21 subjects, 67% experienced a normal normal local reaction, 22% a large local reaction, and 11% a systemic reaction. Epinephrine and norepinephrine plasma levels increased significantly on the first and second challenges. Dopamine plasma levels showed a significant increase on the first challenge only. Plasma catecholamine levels after the second challenge revealed a significant positive correlation between epinephrine increases measured 1 and 2 min after the challenge and the concomitant sting reaction. Basal epinephrine, norepinephrine, and dopamine plasma levels did not differ significantly between patients who experienced different types of sting reactions. Based on our data, we conclude that clinical reactions to in-hospital insect-sting challenges are not affected by early increases in plasma catecholamine levels produced by the expected stress situation.

Adolescent↗

[The special problem of insect venom allergy in childhood].

Natural history of hymenoptera sting allergy is less life threatening in children than in adults. We evaluated a commonly used risk score (allergic reaction to the index sitting, sensitization measured by skin prick test and specific IgE, and specific IgG - maximal 8 points) for its predictability of forthcoming allergic reactions. 93 children with low scores (less than 7 points) experienced stings in field, 96% were save from severe systemic reactions. Of 119 children with high scores (greater than 6 points) receiving rush hyposensitization only 32% developed systemic reactions. We conclude that the score appropriately identifies individuals not to be hyposensitized, but that it overestimates the number of children with a need for hyposensitization. We therefore developed a diagnostic scheme including challenge stings to identify those children who really need hyposensitization.

Adolescent↗

[Kidney function in therapy with non-steroidal antiphlogistic drugs. A double-blind cross-over study with diclofenac, indomethacin and piroxicam].

The effect of piroxicam (1 x 20 mg daily), diclofenac (2 x 50 mg daily) and indomethacin (3 x 25 mg daily) on renal function was compared in a double-blind cross-over study of 33 patients with various rheumatologic diseases. Individuals with preexisting renal impairment were excluded. In 16 patients piroxicam was compared with diclofenac. In another group of 17 patients piroxicam was compared with indomethacin. Each drug was given for 28 days. The mean inhibition of renal prostaglandin E2 by the three drugs was comparable. There was no significant alteration of the renal function parameters in any of the drugs. These results confirm that nonsteroidal antiinflammatory drugs with short (diclofenac, indomethacin) but also with long half life (piroxicam) do not decrease renal function in individuals without renal impairment.

Arthritis, Rheumatoid↗