Vaccination of children with aluminium sensitisation against diphtheria and tetanus presents a problem, since vaccine without aluminium against these potentially serious infectious diseases is no longer available. This case report presents a 7-month-old boy who, after his second immunisation with DTaP-IPV, developed an itching injection site nodule. Before being tested for aluminium sensitisation, he was vaccinated again with DTaP-IPV without developing any reactions. This third vaccine dose was administered intramuscularly.

Physical complaints, such as pain, can be effectively reduced by placebo effects through induction of positive expectations, or increased by nocebo effects through induction of negative expectations. In the present study, verbally induced nocebo and placebo effects on itch were experimentally investigated for the first time. In part 1, the role of verbal suggestions in inducing nocebo effects on itch and pain was investigated. All subjects received the same somatosensory quantitative sensory testing stimuli, that is, mechanical and electrical stimuli and application of histamine, and verbal suggestions to manipulate expectations regarding the stimuli. The suggestions were designed to produce either high expectations for itch (itch nocebo) or pain (pain nocebo) or low expectations for itch (itch nocebo control) or pain (pain nocebo control). Results showed that high itch and pain expectations resulted in higher levels of itch and pain, respectively. When comparing nocebo effects, induced by verbal suggestions, results were more pronounced for itch than for pain. In part 2, verbal suggestions designed to produce a placebo effect on itch (itch placebo) or pain (pain placebo), or neutral suggestions (itch placebo control and pain placebo control) were given regarding a second application of histamine and compared with the first application applied in part 1. Results of placebo effects only showed a significantly larger decrease in itch in the itch placebo condition than in the pain placebo condition. In conclusion, we showed for the first time that nocebo and possibly placebo responses can be induced on itch by verbal suggestions. Experiments of nocebo and placebo effects on itch and pain demonstrated that particularly nocebo effects can be induced on itch and pain by verbal suggestions.

Studies in Gothenburg, Sweden, reported an exceptionally high rate of persistent itching nodules at the site of injection of aluminium containing vaccines, usually with positive epicutaneous tests to aluminium. When a new booster diphtheria-tetanus vaccine was introduced we performed a prospective cluster randomised active surveillance in 25,232 10-year-olds. Parental reports 6 months after vaccination with Duplex or diTeBooster were collected for 22,365 (88%) pupils in 851 schools. We identified 3-6 children per 10,000 with a local itching nodule persisting for at least 2 months. There were no significant differences between the vaccine groups. Contact allergy to aluminium was not detected. The findings support the use of the vaccine presently available in the Swedish vaccination program. Continued surveillance of persistent itching nodules and aluminium contact allergy is, however, warranted for vaccines containing pertussis toxoid and aluminium.

OBJECTIVE:This study was conducted to examine the efficacy of Prrikweg gel, a homeopathic after-bite gel, in relieving the effects of mosquito bites, in particular itching and erythema.

DESIGN:A double-blind, randomized, placebo-controlled clinical trial.

SETTING:London School of Hygiene and Tropical Medicine.

SUBJECTS:100 healthy volunteers.

METHODS:All subjects were bitten under laboratory conditions by Aedes aegypti mosquitoes at one spot on the ventral aspect of the left forearm and another on a corresponding position on the right forearm. One spot was treated with the homeopathic after-bite gel and the other with a placebo gel.

MAIN OUTCOME MEASURES:Itching was assessed on a 5-point discrete rating scale at 0, 0.5, 1, 26.5, and 48 h post-bite to compare the itch-relieving efficacy of the two treatments. Erythema development was assessed by photographing the bite sites, measuring length and width of the erythema with a calliper, and comparing the ratio of the erythema surface at baseline T(0) to the mean erythema surface at 0.5, 1, 26.5, and 48 h post-bite (T mean) for the two treatments.

RESULTS:Testing erythema development by comparing the ratio T(0)/T (mean, after-bite gel) and the ratio T(0)/T (mean, placebo gel) gave a two-tailed p = 0.098(95% Cl, -0.031-0.361) in favour of the after-bite gel. There was not a statistically significant difference between the itch relief provided by the two treatments (two-tailed p = 0.424; 95 percent Cl, -0.541-0.191). The correlation between itching and erythema was significant (r = 0.46; p<0.001). CONCLUSIONS. There are strong indications that the homeopathic after-bite gel reduces erythema development following mosquito bites. The homeopathic mother tinctures of Echinacea angustifolia DC., Ledum palustre L., Urtica urens L. as well as the Hamamelis extract in this gel, whether alone or in combination, are the biologically active ingredients. The homeopathic after-bite gel was not demonstrated to relieve itching; however, based on the correlation between erythema and itching, an effect on itching is not inconceivable.