Hereditary palmoplantar keratoderma: A practical approach to the diagnosis

Abstract

The ridged skin of the palms and soles has several unique features: (i) presence of dermatoglyphics created by alternating ridges and grooves forming a unique pattern, (ii) presence of the highest density of eccrine sweat glands and absence of pilosebaceous units, and (iii) differential expression of keratins compared to the glabrous skin. These features explain the preferential localization of palmoplantar keratoderma (PPK) and several of its characteristic clinical features. PPK develops as a compensatory hyperproliferation of the epidermis and excessive production of stratum corneum in response to altered cornification of the palmoplantar skin due to mutations in the genes encoding several of the proteins involved in it. PPK can manifest as diffuse, focal, striate, or punctate forms per se or as a feature of several dermatological or systemic diseases. There is a wide genetic and phenotypic heterogeneity in hereditary PPK, due to which reaching an accurate diagnosis only on the basis of clinical features may be sometimes challenging for the clinicians in the absence of molecular studies. Nevertheless, recognizing the clinical patterns of keratoderma, extent of involvement, degree of mutilation, and associated appendageal and systemic involvement may help in delineating different forms. Molecular studies, despite high cost, are imperative for accurate classification, recognizing clinical patterns in resource poor settings is important for appropriate diagnosis, genetic counseling, and management. This review intends to develop a practical approach for clinical diagnosis of different types of hereditary PPK with reasonable accuracy.

Siblings with Thickened Palms and Soles

“…The nontransgradient diffuse type include the Vorner and Unna-Thost types, both of which are autosomal-dominant conditions. 1 Mutations in either the keratin 1 (KRT1) or keratin 9 (KRT9) gene have been implicated. 2 Classically, keratoderma starts as patchy thickening in early infancy and gradually progresses by 3-4 years of age to become diffusely thickened, yellowish palmoplantar hyperkeratosis with a sharply demarcated erythematous edge that is typically nontransgradient.…”

“…Other features include hyperhidrosis with a tendency to develop secondary fungal and bacterial infections, and pitted keratolysis associated with itchiness and malodor. 1 This condition persists for life and can be passed on to the next generation; hence, appropriate genetic counseling is recommended. Emollients, keratolytic agents, topical retinoids, or topical vitamin D are used to soften the hyperkeratotic skin, and any superimposed secondary infection is treated accordingly.…”

“…Thyroglossal duct cyst is a common congenital pathology in the pediatric population. 1 In the absence of treatment, it can be complicated by infection or fistulization and malignancy. 2 The diagnosis is clinical, although it is usually supported by imaging tests such as cervical ultrasound scan.…”

Hereditary epidermolytic palmoplantar keratosis due to a novel desmoglein‐1 mutation: A case report

“…Hereditary palmoplantar keratodermas (PPKs) are classified either by their genetic mutation or by their clinical picture. The importance of identifying isolated forms from syndromic entities has major clinical and therapeutic relevance 1 . More than 69 different forms of PPK are known and can involve mutations in keratin ( KRT ), which are generally the most common subtypes and cause more diffuse forms often linked to epidermolytic ichthyosis 2 .…”

Naxos disease: The model for scientific discovery

“…Tissues exposed to greater mechanical stress, such as the heart, palmoplantar skin, and skin appendages, have larger desmosomes with increased protein expression. [ 9 ] Therefore, they are more susceptible to injury. Disruption to desmosome structures impairs the integrity of the cardiac functional syncytium, resulting in arrhythmias.…”