Randomized controlled pilot trial with ion-exchange water softeners to prevent eczema (SOFTER trial).

BACKGROUND: Observational studies suggest an increased risk of eczema in children living in hard versus soft water areas, and there is, therefore, an interest in knowing whether softening water may prevent eczema. We evaluated the feasibility of a parallel-group assessor-blinded pilot randomized controlled trial to test whether installing a domestic ion-exchange water softener before birth in hard water areas reduces the risk of eczema in infants with a family history of atopy. METHODS: Pregnant women living in hard water areas (>250 mg/L calcium carbonate) in and around London UK, were randomized 1:1 antenatally to either have an ion-exchange water softener installed in their home or not (ie to continue to receive usual domestic hard water). Infants were assessed at birth and followed up for 6 months. The main end-points were around feasibility, the primary end-point being the proportion of eligible families screened who were willing and able to be randomized. Clinical end-points were evaluated including frequency of parent-reported doctor-diagnosed eczema and visible eczema on skin examination. Descriptive analyses were conducted, and no statistical testing was performed as this was a pilot study. RESULTS: One hundred and forty-nine families screened were eligible antenatally and 28% (41/149) could not have a water softener installed due to technical reasons or lack of landlord approval. Eighty of 149 (54%) were randomized, the primary end-point. Two participants withdrew immediately after randomization, leaving 39 participants in each arm (78 total). Attrition was 15% (12/78) by 6 months postpartum. All respondents (n = 69) to the study acceptability questionnaire reported that the study was acceptable. Fifty-six of 708 (7.9%) water samples in the water softener arm were above the hard water threshold of 20 mg/L CaCO3 . At 6 months of age 27/67 infants (40%) developed visible eczema, 12/36 (33%) vs. 15/31 (48%) in the water softener and control groups, respectively, difference -15% (95% CI -38, 8.3%), with most assessments (≥96%) remaining blinded. Similarly, a lower proportion of infants in the water softener arm had parent-reported, doctor-diagnosed eczema by 6 months compared to the control arm, 6/17 (35%) versus 9/19 (47%), difference -12% (95% CI -44, 20%). CONCLUSION: A randomized controlled trial of water softeners for the prevention of atopic eczema in high-risk infants is feasible and acceptable. TRIAL REGISTRATION: NCT03270566 (clinicaltrials.gov).

What does acne genetics teach us about disease pathogenesis?

BACKGROUND: Acne vulgaris is a highly prevalent inflammatory skin disorder with a complex pathogenesis, characterized by comedones, papules, pustules and nodules. Familial preponderance clearly indicates a genetic basis for acne vulgaris, but until recently solid genetic associations were lacking. RESULTS: The advent of high-resolution genotyping array technologies has allowed for large-scale studies with both family-based and cross-sectional designs. These studies have revealed genetic loci encompassing genes that could be active in biological pathways and processes underlying acne vulgaris. However, specific functional consequences of those variants remain elusive. In parallel, investigations into rare disorders and syndromes that incorporate features of acne or acne-like lesions have recently accelerated our understanding of disease pathogenesis. The genes revealed by these rare disorders highlight mechanisms cardinal for pilosebaceous biology and therefore anchor our insights from genetic association studies for acne vulgaris. CONCLUSIONS: The next phase of research will require more in-depth mechanistic investigations of loci and genes implicated in acne phenotypes to define the key molecular players driving the disorder. Concurrently, new treatments for acne vulgaris could be developed by dissecting the candidate molecular pathways to identify druggable targets.

Filaggrin mutations are associated with recurrent skin infection in Singaporean Chinese patients with atopic dermatitis.

BACKGROUND: Loss-of-function (null) mutations within the filaggrin (FLG) gene are a strong risk factor for atopic dermatitis (AD). We hypothesized that the absence or reduction of the filaggrin protein could compromise skin barrier and increase patients' susceptibility to recurrent skin infection. OBJECTIVES: To investigate the association between FLG-null mutations and the risk of recurrent skin infection among a series of patients with AD in Singapore. METHODS: This study included 228 Singaporean Chinese patients with AD with at least 1year of follow-up at the time of recruitment between January 2008 and December 2009 at the National Skin Centre in Singapore. Each patient had their medical records reviewed for history of skin infection in the preceding year and was genotyped for 22 FLG-null mutations. RESULTS: Compared with those without the FLG-null mutations, patients with AD who had FLG mutation(s) had approximately a seven times increased risk of more than four episodes of skin infection requiring antibiotics in the past year (odds ratio 6·74; 95% confidence interval 2·29-19·79). This risk was much greater in those with mild or moderate disease, and was present in both users and nonusers of oral steroids. CONCLUSION: This study highlights a novel association between FLG-null mutations and an increased susceptibility to recurrent bacterial skin infection among patients with AD.

Wide spectrum of filaggrin-null mutations in atopic dermatitis highlights differences between Singaporean Chinese and European populations.

BACKGROUND: Null mutations in the filaggrin gene (FLG) cause ichthyosis vulgaris (IV) and predispose to atopic dermatitis (AD). Cohort studies in Europe and Japan have reported an FLG mutation carrier frequency of between 14% and 56%, but the prevalent European FLG mutations are rare or absent in Chinese patients with IV and AD. OBJECTIVES: To investigate further the spectrum of FLG-null mutations in Chinese patients and to compare it with that in other populations. METHODS: We conducted comprehensive FLG genetic analysis in a discovery cohort of 92 Singaporean Chinese individuals with IV and/or moderate-to-severe AD. All detected FLG mutations were then screened in a cohort of 425 patients with AD and 440 normal controls. Results In total, 22 FLG-null mutations, of which 14 are novel, were identified in this study; the combined null FLG genotype of 17 mutations detected in cases and controls showed strong association with AD [Fisher's exact test; P = 5·3 × 10⁻9; odds ratio (OR) 3·3], palmar hyperlinearity (Fisher's exact test; P = 9·0 × 10⁻¹5; OR 5·8), keratosis pilaris (Fisher's exact test; P = 0·001; OR 4·7) and with increased severity of AD (permutation test; P = 0·0063). CONCLUSIONS: This study emphasizes the wider genetic landscape of FLG-null mutations in Asia that is slowly emerging.

A case of dermatopathia pigmentosa reticularis with wiry scalp hair and digital fibromatosis resulting from a recurrent KRT14 mutation.

We report a patient of Malay ancestry with dermatopathia pigmentosa reticularis (DPR) resulting from a recurrent KRT14 p.R125C mutation. The patient has reticulate hyperpigmentation over his trunk and proximal limbs, together with onychodystrophy. Despite the absence of noncicatricial alopecia, he has acral nonscarring blisters, palmoplantar hyperkeratosis and hypoplastic dermatoglyphics, in addition to unusual abnormalities such as wiry scalp hair and digital fibromatous thickening.

Specific loss of connexin 26 expression in ductal sweat gland epithelium associated with the deletion mutation del(GJB6-D13S1830).

A whole array of cutaneous syndromes is associated with distinct dominant mutations in GJB2 encoding the gap junction protein connexin 26 (C x 26), including Vohwinkel's syndrome and keratitis-ichthyosis-deafness syndrome. In contrast, recessive GJB2 mutations occur in a large proportion of individuals with hearing loss but no obvious dermatological phenotype. Recently, a large deletion of approximately 342 kb, encompassing the coding region of GJB6 encoding C x 30, but not affecting GJB2, was shown to be associated with hearing loss. From analysis of patient skin, we provide immunohistochemical and bioinformatic data to show that the expression of C x 26 is affected by del(GJB6-D13S1830) in a cell-type-specific manner within the sweat gland. This putative regulatory element of C x 26 expression may be a key factor related to the severe or profound deafness associated with del(GJB6-D13S1830).

Diagnosis and confirmation of epidermolytic palmoplantar keratoderma by the identification of mutations in keratin 9 using denaturing high-performance liquid chromatography.

BACKGROUND: Epidermolytic palmoplantar keratoderma (EPPK) is one of a number of disorders characterized by diffuse thickening of palm and sole skin. Although EPPK is not a life-threatening condition, palmoplantar keratoderma can be associated with cancer and heart disease and therefore differential diagnosis is important so that adequate surveillance can be provided for the more serious conditions. Most cases of EPPK are caused by mutations in the gene encoding the palm- and sole-specific keratin 9 (K9), and this provides an option for molecular diagnosis of this condition. OBJECTIVES: To identify the molecular basis of diffuse palmoplantar keratoderma in four British families. METHODS: Denaturing high-performance liquid chromatography (dHPLC) and DNA sequencing were used to screen exon 1 of the k9 gene for sequence variations. RESULTS: The dHPLC profiles obtained from individuals with EPPK differed from control samples, indicating sequence variations within the fragment analysed. The profiles varied between families, suggesting that underlying mutations were different for each family; this was confirmed by DNA sequencing. In three cases previously reported mutations were found that resulted in the change of methionine156 to valine and arginine162 to either tryptophan or glutamine. A novel mutation was identified in a fourth family that changed valine170 to methionine. dHPLC was used to screen control samples for this sequence variation and confirmed that it was not a common polymorphism. CONCLUSIONS: These results confirm the diagnosis of EPPK in these families and underline the usefulness of dHPLC as a method of screening samples for heterozygous mutations.

Connexin 26 expression and mutation analysis in epidermal disease.

Gap junctional communication has a key role in the co-ordination of keratinocyte differentiation. Multiple connexins are expressed in the epidermis and mutations in four of these connexins are associated with disorders of keratinisation. Specific autosomal dominant Cx26 mutations have been associated with syndromes of skin disease and hearing loss. Here we describe the characterization of a new Cx26 polyclonal antibody raised against the cytoplasmic region of the protein. It has been used to investigate Cx26 protein localization in epidermal disease and in the study of mutant Cx26 proteins.