Erythema multiforme (EM) is an acute self-limited immune-mediated reaction manifested by target skin lesions with mucous membrane involvement. The most common causes are infections and drugs. Vaccinations have been reported as a triggering factor, and they may be a frequent cause of EM in childhood. A 19-year-old female developed several target lesions of the hands and feet 10 days after the second dose of human papillomavirus (HPV) vaccine. Clinico-histologically, a diagnosis of EM minor was made. Treatment with topical corticosteroids and oral antihistamines resulted in complete clearance of the rash. Four months later, she received the last booster dose of the vaccine. A few subtle lesions appeared and disappeared spontaneously after a few days. Gardasil is a non-infectious vaccine, developed for the prevention of cervical cancer, precancerous genital lesions and genital warts. It delivers the major capsid (L1) protein of HPV types 6, 11, 16 and 18. Mild local reactions are the main adverse events. The only serious events are very rare cases of anaphylaxis. In our patient, the temporal relationship between the development of EM and the vaccination suggests that the HPV vaccine probably was the causal agent. This is the first published case of EM following HPV vaccination.

Erythema multiforme is a cutaneous reaction pattern precipitated by varied agents, notably herpes simplex and drugs. It predominantly occurs in adolescents and young adults but may be seen at other ages also. While vaccination is rarely a precipitating factor for erythema multiforme, it may occasionally be seen in infants and children. We report here a case of a two month-old infant with lesions of erythema multiforme minor appearing after two weeks following vaccination for DPT, Hepatitis B and influenza.

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.