Smallpox vaccination site complications

The typical resolution of the smallpox vaccination site is a smooth scar, a sequela that is discussed during prevaccination counseling. In addition, other types of lesion may develop at the scar site, including short- or long-term benign and malignant changes, as reviewed below. Although current recommendations do not discuss potential scar complications or scar surveillance, healthcare providers would benefit from an awareness of these potential complications, and should consider periodic scar surveillance as part of a general physical examination.     

Scrofuloderma after BCG vaccination

A 7-month-old boy with scrofuloderma following BCG vaccination is presented. He had a 2 cm x 1 cm erythematous lesion with a sinus tract in the right cervical area. In addition, he had ulcerated erythematous lesions 0.5 cm x 0.5 cm in size on the left deltoid area and left forearm where BCG vaccination and a PPD test were performed, respectively. Histopathologic findings were consistent with the clinical diagnosis.     

Merthiolate hypersensitivity and vaccination

Epicutaneous tests with 0.1% merthiolate in petrolatum showed hypersensitivity in 96 of 4647 eczema patients (2.0%) and in seven of 105 healthy recruits (7%). There was a marked preponderance of young age classes in the eczema group. Twelve of 41 merthiolate-positive patients tested reacted to mercury alone, three to thiosalicylic acid alone and one to both. The remaining 25 patients reacted to neither of the individual components although the merthiolate complex as a whole gave a positive test result. Forty-five of the merthiolate-positive patients were tested subcutaneously with 0.5 ml of a 0.01% merthiolate solution, i.e. a dose equal to that contained in one shot of tetanus toxoid, for example. Nine patients developed a local reaction at the site of the injection, and the area became eczematous in four cases. In one of the patients the eczema spread over the body, causing fever. Since merthiolate-sensitive patients also react to merthiolate administered intracutaneously, the vaccinator should avoid the use of a needle whose outer surface has been contaminated when the vaccine was aspirated from the bottle. However, even when this precautionary measure is taken, local reactions can be expected in such a high percentage of merthiolate-sensitive persons that merthiolate in vaccines should be replaced by another antibacterial agent.     

Granuloma annulare following BCG vaccination

BACKGROUND: Granuloma annulare following BCG vaccination or tuberculin skin tests is rarely reported in the literature. We describe three cases occurring in patients under the age of 6 years. CASE REPORTS: In the first two cases, granuloma annulare was initially localized at the vaccinal site, then generalized. In the third case, diagnosis was deep granuloma annulare localized far from the initial vaccination site, with recurrence following tuberculin test. In the three cases, diagnosis was made on the basis of clinical and histological elements. DISCUSSION: The relationship between granuloma annulare and BCG may seem evident when the eruption occurs at the vaccinal site, but remains difficult to prove. Diagnosis essentially relies on the absence of other classical etiologies and a compatible delay. When a vaccination such as BCG appears to be the cause of granuloma annulare, a possible cause would be injection trauma or a cell-mediated-delayed-hypersensitivity reaction to a specific antigen contained in the vaccine, leading to development of skin disorders such as granuloma annulare in predisposed subjects. Reports of granuloma annulare following BCG are uncommon but the incidence may be underestimated. In practice, diagnosis of granuloma annulare following BCG or tuberculin skin test cannot be established until BCG dissemination infection is ruled out, a necessary clinical and paraclinical step required in all cases of eruptions following this vaccination. Granuloma annulare is a benign complication requiring no treatment and does not constitute a contraindication for other usual vaccinations.