Ichthyoses - Part 1: Differential diagnosis of vulgar ichthyoses and therapeutic options

Ichthyoses-A Clinical and Pathological Spectrum from Heterogeneous Cornification Disorders to Inflammation

Ichthyoses are inborn keratinization disorders affecting the skin only (non-syndromic) or are associated with diseases of internal organs (syndromic). In newborns, they can be life-threatening. The identification of the gene defects resulted in reclassification and a better understanding of the pathophysiology. Histopathologic patterns include orthohyperkeratosis with a reduced or well-developed stratum granulosum, hyperkeratosis with ortho- and parakeratosis with preserved or prominent stratum granulosum, and epidermolytic ichthyosis. Another pattern features “perinuclear vacuoles and binucleated keratinocytes”, which is associated with keratin mutations. Some ichthyoses are histologically defined by psoriasis-like features, and distinct subtypes show follicular hyperkeratosis. In addition to histological and immunohistochemical methods, these patterns allow a better histopathologic diagnosis.

Ichthyosis with confetti: a rare diagnosis and treatment plan

Congenital ichthyosis includes a group of rare skin disorders known for tiles of hyperkeratotic skin resembling fish scales. With age, the hyperkeratosis generally becomes more concentrated around joints which increases impairment. Ichthyosis with confetti, also known as ichthyosis variegata or congenital reticular ichthyosiform erythroderma, is an extremely rare form of ichthyosis. It usually begins as non-bullous congenital ichthyosiform erythroderma with the expected scaling. However, with time patients develop widespread 'confetti-like' patches of healthy skin. The healthy skin reflects clonal expansion of 'normal' or reverted cells. Cell reversion has potential for future therapies using revertant stem cells. Controlling symptoms with emollients is the goal of treatment for ichthyosis since it has no cure.

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.