Direct infant ultraviolet light exposure is associated with eczema and immune development: a critical appraisal

AIM

Rueter et al. aimed to 'determine the effects of early postnatal vitamin D supplementation on infant eczema and immune development'.

SETTING AND DESIGN

This was a double-blind randomized placebo-controlled trial with an additional nonrandomized exploratory analysis on the effects of ultraviolet (UV) exposure led from a hospital setting.

STUDY EXPOSURE

Vitamin D (400 iU daily) drops or placebo drops (coconut and palm kernel oil) were allocated randomly to 195 infants born to families with a first-degree relative with atopic disease. Eighty-six of these infants were allocated personal UV dosimeters in a nonrandomized fashion to measure UV light (290-380 nm) exposure until 3 months of age.

OUTCOMES

Eczema and wheeze were assessed at 3 and 6 months, and 25 immune function markers were assessed at 6 months of age. Infant vitamin D levels and immune functions were measured at 6 months of age.

RESULTS

Although vitamin D levels were significantly greater in infants in the intervention group than in those in the placebo group at 3 and 6 months of age, there was no difference in eczema between groups at either time point (10·0% vs. 6·7% at 3 months and 21·8 vs. 19·3% at 6 months for the vitamin D and placebo groups, respectively). In the subset of infants given a dosimeter, those with eczema had less UV light exposure (median 555 J m^-2 ) than infants who did not develop eczema (median 998 J m^-2 ). Across the 25 immune functions, UV light exposure was inversely correlated with interleukin-2, granulocyte macrophage colony-stimulating factor and eotaxin production by Toll-like receptor ligands.

CONCLUSIONS

Vitamin D supplementation in high-risk infants increased vitamin D levels but did not reduce eczema. Exploratory post-hoc analyses in a nonrandomized subset showed an association between greater direct UV light exposure and reduction of eczema. The authors claim that their 'findings indicate that UV light exposure appears more beneficial than vitamin D supplementation as an allergy prevention strategy in early life'.

Pseudomonas aeruginosa meningitis/ventriculitis in a UK tertiary referral hospital

BACKGROUND

Pseudomonas aeruginosa is a rare cause of meningitis and ventriculitis but is generally associated with significant morbidity and mortality.

AIM

We sought to determine the epidemiology, risk factors and outcome of meningitis and ventriculitis due to P. aeruginosa at our institution in order to inform preventive strategies and treatment guidelines.

METHODS

Retrospective study of all patients with a positive cerebrospinal fluid (CSF) culture admitted to a tertiary care hospital over 18 years. Clinical details, demographic, microbiological and antibiotic data were obtained from laboratory and medical records.

RESULTS

Twenty-four episodes occurred in 21 patients over 18 years. Pyrexia (75%), fluctuating mental status (50%) and headache (41%) were the most frequent presenting symptoms. Nineteen of the 21 patients had previously undergone a neurosurgical procedure and seven had extra-ventricular devices in situ. Twelve (57%) patients had P. aeruginosa isolated from another site prior to their episode. Most (89%) CSF samples demonstrated a neutrophilia; the CSF protein, when measured, was raised in all cases. Gram-negative bacilli were visible on CSF microscopy in only three isolates. There were relatively low rates of resistance to most antimicrobials tested and combination treatment of intravenous with intrathecal antibiotics was often used. No patients died within 28 days.

CONCLUSION

Pseudomonas aeruginosa meningitis and ventriculitis are predominantly nosocomial and related to prior neurosurgery. It can be difficult to diagnose as CSF Gram-film and meningism are insensitive markers. Appropriate empirical treatment, neurosurgical prophylaxis and surveillance can aid in managing this infection.