Clinico-epidemiological features of primary hereditary ichthyoses in the Eastern province of Saudi Arabia

Ichthyosis

The ichthyoses are a large, heterogeneous group of skin cornification disorders. They can be inherited or acquired, and result in defective keratinocyte differentiation and abnormal epidermal barrier formation. The resultant skin barrier dysfunction leads to increased transepidermal water loss and inflammation. Disordered cornification is clinically characterized by skin scaling with various degrees of thickening, desquamation (peeling) and erythema (redness). Regardless of the type of ichthyosis, many patients suffer from itching, recurrent infections, sweating impairment (hypohidrosis) with heat intolerance, and diverse ocular, hearing and nutritional complications that should be monitored periodically. The characteristic clinical features are considered to be a homeostatic attempt to repair the skin barrier, but heterogeneous clinical presentation and imperfect phenotype-genotype correlation hinder diagnosis. An accurate molecular diagnosis is, however, crucial for predicting prognosis and providing appropriate genetic counselling. Most ichthyoses severely affect patient quality of life and, in severe forms, may cause considerable disability and even death. So far, treatment provides only symptomatic relief. It is lifelong, expensive, time-consuming, and often provides disappointing results. A better understanding of the molecular mechanisms that underlie these conditions is essential for designing pathogenesis-driven and patient-tailored innovative therapeutic solutions.

Updated strategies for the management, pathogenesis and molecular genetics of different forms of ichthyosis syndromes with prominent hair abnormalities

Syndromic ichthyosis is rare inherited disorders of cornification with varied disease complications. This disorder appears in seventeen subtypes associated with severe systematic manifestations along with medical, cosmetic and social problems. Syndromic ichthyosis with prominent hair abnormalities covers five major subtypes: Netherton syndrome, trichothiodystrophy, ichthyosis hypotrichosis syndrome, ichthyosis hypotrichosis sclerosing cholangitis and ichthyosis follicularis atrichia photophobia syndrome. These syndromes mostly prevail in high consanguinity states, with distinctive clinical features. The known pathogenic molecules involved in ichthyosis syndromes with prominent hair abnormalities include SPINK5, ERCC2, ERCC3, GTF2H5, MPLKIP, ST14, CLDN1 and MBTPS2. Despite underlying genetic origin, most of the health professionals solely rely on phenotypic expression of these disorders that leads to improper management of patients, hence making these patients living an orphanage life. After dermal features, association of other systems such as nervous system, skeletal system, hair abnormalities or liver problems may sometimes give clues for diagnosis but still leaving place for molecular screening for efficient diagnosis. In this paper, we have presented a review of ichthyosis syndrome with prominent hair abnormalities, with special emphasis on their updated genetic consequences and disease management. Additionally, we aim to update health professionals about the practice of molecular screening in ichthyosis syndromes for appropriate diagnosis and treatment.

Harlequin ichthyosis: a case report of prolonged survival

Harlequin ichthyosis (HI) is a rare type of congenital ichthyosis associated with poor survival. We report, with photographic record, a male baby born with HI. To the best of our knowledge, this is the first reported case of HI in Saudi Arabia, where the child has survived beyond 7 years. The baby was born at 37 weeks of gestation from consanguineous parents with no inherited skin disorder in the family. The mother was 28 years old with three normal previous pregnancies and healthy babies. At birth, the baby's skin had thick scales separated by deep fissuring. He was managed in intensive care with supportive treatment and frequent application of lubricants, emollients and urea cream. The skin gradually became softened, and began to shed after 6 weeks. After 8 months of inpatient management, he was discharged. He is currently 7 years old and is still being treated for non-bullous congenital ichthyosiform erythroderma.

Prevalence of inherited ichthyosis in France: a study using capture-recapture method

BACKGROUND

Inherited ichthyoses represent a group of rare skin disorders characterized by scaling, hyperkeratosis and inconstant erythema, involving most of the tegument. Epidemiology remains poorly described. This study aims to evaluate the prevalence of inherited ichthyosis (excluding very mild forms) and its different clinical forms in France.

METHODS

Capture - recapture method was used for this study. According to statistical requirements, 3 different lists (reference/competence centres, French association of patients with ichthyosis and internet network) were used to record such patients. The study was conducted in 5 areas during a closed period.

RESULTS

The prevalence was estimated at 13.3 per million people (/M) (CI95%, [10.9 - 17.6]). With regard to autosomal recessive congenital ichthyosis, the prevalence was estimated at 7/M (CI 95% [5.7 - 9.2]), with a prevalence of lamellar ichthyosis and congenital ichthyosiform erythroderma of 4.5/M (CI 95% [3.7 - 5.9]) and 1.9/M (CI 95% [1.6 - 2.6]), respectively. Prevalence of keratinopathic forms was estimated at 1.1/M (CI 95% [0.9 - 1.5]). Prevalence of syndromic forms (all clinical forms together) was estimated at 1.9/M (CI 95% [1.6 - 2.6]).

CONCLUSIONS

Our results constitute a crucial basis to properly size the necessary health measures that are required to improve patient care and design further clinical studies.

Resource utilization and quality of life associated with congenital ichthyoses

We explored resource utilization (ResUtil) and quality of life (QOL) associated with congenital ichthyoses (CI). Subjects completed an online survey related to clinical severity, demographics, ResUtil, and QOL as measured according to the Dermatology Life Quality Index (DLQI). Validated Likert scales were used to evaluate severity of hyperkeratosis, erythema, and alopecia. ResUtil was determined according to time spent daily treating CI symptoms (TimeTx) and number of ichthyosis-related dermatology visits (DermVisits) per year. We used linear regression to investigate predictors of a transformed DLQI (sqrtDLQI) and logistic regression for ResUtil. Of 235 subjects, 60.2% were female, 83.8% were Caucasian, 42.3% had a family history (FamHx) of CI, and the mean age was 28.7 years (SD 20.3). Predictors for worse QOL were hyperkeratosis severity (β = 0.27, p < 0.01), erythema (β = 0.27, p < 0.01), TimeTx (β = 0.21, p < 0.01), ichthyosis type (β = 0.09, p < 0.01), and age (β = 0.01, p = 0.02). Predictors for DermVisits were hyperkeratosis severity (odds ratio [OR] = 1.38, 95% confidence limit [CL] = 1.01, 1.87), FamHx (OR = 0.28, 95% CL = 0.09, 0.85), age (OR = 0.97, 95% CI = 0.96, 0.99), and alopecia severity (OR = 1.43, 95% CL = 1.12, 1.82). Predictors for treatment duration were erythema (OR = 1.35, 95% CL = 1.02, 1.78), age (OR = 0.98, 95% CL = 0.96, 0.99), and DLQI (OR = 1.09, 95% CL = 1.03, 1.15). Increased hyperkeratosis severity and erythema negatively impact QOL in the CI. Furthermore, increased disease severity predicted greater ResUtil, whereas increased age and FamHx predicted less ResUtil. Our findings suggest that better therapies and increased patient education may improve QOL and decrease ResUtil.