KID syndrome associated with elevated sweat chloride

Elevated sweat chloride concentration in children without cystic fibrosis who are receiving topiramate therapy

BACKGROUND

Topiramate, which is used as an anticonvulsant and for migraine prophylaxis in children, causes oligohydrosis as a side-effect, but its effect on sweat chloride concentrations has not been studied systematically.

METHODS

Twenty-one children receiving topiramate and 20 healthy controls with no signs or symptoms of pulmonary or gastrointestinal disease and a negative family history for cystic fibrosis (CF) underwent bilateral pilocarpine iontophoresis and sweat collection via Macroduct® system.

RESULTS

Adequate samples (>15 µl volume) were obtained from 17/19 topiramate subjects (89%), and 19/20 (95%) controls. The mean sweat chloride concentration was 37.7 ± 18.8 mmol/L for patients receiving topiramate, and 15.9 ± 6.9 mmol/L for controls (p = 0.0001). The mean sweat volume was 29.1 ± 17.4 µl for patients receiving topiramate, and 41.2 ± 17.5 µl for controls (p = 0.037). Overall 8/17 (47%) of patients on topiramate with a measurable sweat chloride had either an intermediate (>40 mmol/L but <60 mmol/L) or elevated (>60 mmol/L) sweat chloride test result, while 0/19 control subjects had elevated sweat chloride (p = 0.0008). Further analysis of the in vitro activity of topiramate on cultured human bronchial epithelial cells in modified Ussing chambers showed no differences in chloride conductance measured in cells exposed to 10 or 50 µg/ml of topiramate when compared to non-exposed cells.

CONCLUSIONS

This is the first report of a medication affecting sweat chloride values and shows that topiramate therapy can cause elevated sweat chloride concentrations in the absence of clinical manifestations of CF.

Fatal septicemia in an infant with keratitis, ichthyosis, and deafness (KID) syndrome

Keratitis, ichthyosis, and deafness (KID) syndrome is a rare congenital disorder of unknown etiology in which increased susceptibility to viral, bacterial, and mycotic infections has been observed. We report an infant with KID syndrome who died from overwhelming systemic infection. To date, investigations into the immune function of patients with this syndrome have not revealed a common underlying systemic immune deficit. However, the severity of infections and multiplicity of organisms observed in this syndrome suggest that a primary immunodeficiency is present in addition to an impaired cutaneous barrier to microorganisms.

Auditory manifestations of Keratitis-Ichthyosis-Deafness (KID) syndrome

OBJECTIVE

Evaluation of the auditory manifestations of Keratitis-Ichthyosis-Deafness (KID) syndrome, a rare genodermatosis characterized by follicular hyperkeratosis, vascularizing keratitis, and congenital hearing loss.

STUDY DESIGN

Five individuals with sporadic KID syndrome were evaluated in the outpatient audiology clinic at the Warren Grant Magnuson Clinical Center of the National Institutes of Health.

METHODS

Audiologic examinations included pure-tone audiometry, speech audiometry, and middle ear immittance testing. Auditory brainstem responses and otoacoustic emissions were analyzed in 2 subjects.

RESULTS

Four subjects had prelingual, bilateral, profound sensorineural hearing loss, whereas the fifth subject had significant residual hearing that exhibited no progression on serial audiograms. All 5 subjects had a history of non-erosive keratosis obturans and cutaneous cysts in the external ear canals that prevented continuous use of ear molds.

CONCLUSIONS

The sensorineural hearing loss in KID syndrome is generally prelingual and profound. This combination of auditory and cutaneous phenotypes is similar to those previously reported for KID syndrome. KID syndrome presents a difficult challenge for communication rehabilitation because keratitis may impair the perception of sign and spoken language, and the cutaneous manifestations routinely curtail use of external amplification devices.