Koilonychia: an update on pathophysiology, differential diagnosis and clinical relevance

Pediatric Nail Disorders

Background

Pediatric nail disorders encompass a broad range of conditions. This article aimed to consolidate current knowledge on pediatric nail disorders to enhance diagnostic proficiency and clinical management among healthcare professionals.

Summary

Pediatric nail disorders present a diagnostic challenge due to their diverse nature. Non-syndromic congenital nail disorders encompass various anomalies such as anonychia/hyponychia, congenital malalignment of the great toenail, and racket thumbs, each with distinct clinical presentations and genetic associations. Syndromic congenital nail disorders, often part of complex syndromes, are characterized by unique features and associated abnormalities. Acquired nail diseases in children, like Beau's lines and onychomadesis, typically result from trauma or infection, while melanonychia, although rare in children, requires careful monitoring for potential malignant alterations, with consideration for biopsy in cases with concerning features.

Key Messages

(1) Pediatric nail disorders may pose diagnostic challenges and require a comprehensive understanding of nail anatomy and development. (2) Congenital nail disorders encompass isolated anomalies and syndromic associations, necessitating thorough evaluation for associated systemic conditions. (3) Acquired nail diseases may indicate underlying trauma or systemic illness and require careful assessment.(4) Melanonychia in children requires ongoing monitoring and evaluation, emphasizing the importance of consistent follow-up and histopathological examination when necessary.

Examination of the nails: Main signs

Understanding the anatomy of the nail apparatus is a prerequisite for diagnosing and managing various nail disorders. The latter may be associated with systemic pathologies, or accompany infectious, inflammatory, tumoral, toxic or traumatic dermatoses. Before attempting to identify the cause, a rigorous clinical examination should be conducted to screen for elementary lesions that may affect general nail shape, nail surface, subungual attachments, periungual soft tissue or nail color. All of these guide differential diagnosis.

Congenital nail abnormalities

Congenital nail disorders are an uncommon presenting symptom which can be difficult to diagnose and manage. Nail diseases in the pediatric population differ from those in adults in terms of diagnosis, approach and management. In most cases, they do not require treatment and resolve with growth. Physicians need to be able to recognize them, to reassure the parents. The most frequently encountered pathologies associated with nail disorder are syndactyly, acrosyndactyly, symbrachydactyly, macrodactyly, Wassel I thumb duplication, Kirner's deformity and congenital onychodysplasia of the index finger. Treatment usually consists in surgical correction of the deformity. Nail malformation can also be an aspect of a systemic disease. It may provide a clue for screening, and should not be overlooked. Nail conditions can be the first sign of nail-patella syndrome, ectodermal dysplasia, dyskeratosis congenita, epidermolysis bullosa, pachyonychia congenita or lung disease. Medical treatment is therefore discussed on a case-by-case basis.

Recognizing skin conditions in patients with cirrhosis: a narrative review

Background: The skin is a major target organ for extrahepatic manifestations of liver diseases, and dermatologic abnormalities are common in patients with hepatic disorders. Clinical examination of the skin, nails and hair can allow for appropriate recognition, early diagnosis and treatment of liver diseases, and improvement in the quality of life and life expectancy of affected patients.Methods: We searched 3 databases (Pubmed,Medline and Embase) and selected studies about cirrhosis related skin manifestations and their pathophysiology.Results: A total of 73 articles were included in the review. Studies displayed the spectrum of cutaneous manifestations related to hormonal and vascular changes as well as nail and hair changes in patients with cirrhosis and/or portal hypertension.Conclusion: Cutaneous alterations are important clues or potential indications in the diagnosis of liver cirrhosis. Familiarity with skin conditions can be promptly diagnosed and appropriate management initiated.KEY MESSAGESManifestations of the liver and skin disorders are interrelated in various ways. Cutaneous changes may be the first clue that a patient has liver disease.The skin is a major target organ for extrahepatic manifestations of liver diseases. A broad range of cutaneous alterations can be present in patients with cirrhosis, such as vascular, nail, hair, hormonal changes, etc.Recognizing these signs is crucial so that potential underlying diseases including liver disease can be promptly diagnosed and appropriate management timely initiated.

The Physical Examination to Assess for Anemia and Hypovolemia

Hypovolemia develops with the loss of extracellular fluid volume or blood. Rapidly identifying hypovolemia can be lifesaving. Indicators of hypovolemia on examination include supine or postural hypotension, increase in heart rate by 30 beats per minute or severe dizziness with standing, and a decrease in central venous pressure detected on visual inspection of the jugular venous pressure or ultrasound assessment of the inferior vena cava or internal jugular veins. Other findings with utility include a dry axilla and dry oral mucosa. With chronic anemia, hemodynamic changes detectable on examination may be minimal, as the body compensates by retaining extracellular volume.

Cutaneous signs of nutritional disorders

This review article focuses on the dermatologic manifestations of selected nutrient deficiencies, including protein-energy and micronutrient-related malnutrition. The various nutrient deficiencies presented may share common features. However, distinctive cutaneous signs may prompt clinicians to consider a nutritional cause and help distinguish a nutrient deficiency from other common dermatologic conditions. The recent reemergence of forgotten nutritional deficiencies, such as scurvy and pellagra, in the context of predisposing risk factors that may uniquely affect women more than men makes this topic timely. Recognition of nutritional disorders is important because appropriate treatment may reverse cutaneous signs and prevent irreversible sequelae.

Identification of two novel mutations in the PLCD1 gene in Chinese patients with hereditary leukonychia

Hereditary leukonychia (HL) is a rare nail dystrophy disease, and several different clinical manifestations and mutations in the phospholipase C δ 1 (PLCD1) gene have been reported. The present study reports on one Chinese family and one sporadic case of with HL. The family members exhibited an autosomal dominant pattern of inheritance with the involvement of all the fingers and toenails in all the patients. Of interest, most of the affected members had koilonychia during their childhood. Thus, the present study first used gene mapping with an aim to identify the pathogenic gene underlying koilonychia. Through genome‑wide linkage analysis, the pathogenic area of koilonychia was identified on chromosome 3 with multipoint Log of Odds scores >2. A novel pathogenic mutation c.1384G>A (p.E462K) was identified in the PLCD1 gene in all the patients in the family, which confirmed the diagnosis of hereditary leukonychia. A novel mutation c.770G>A (p.R257H) was also detected in one sporadic case of leukonychia. On the basis of these findings and of previous studies, it is suggested that hereditary leukonychia may initially present as koilonychia, whereas hereditary koilonychia does not progress to leukonychia. Moreover, the present study identified two pathogenic variants of the PLCD1 associated with hereditary leukonychia, and highlights the significance of genetic diagnosis.

Transient Cutaneous Alterations of the Newborn

Neonatal cutaneous alterations are common, usually appearing at birth or during the first few days of life. Most of these conditions are physiological, benign, and transient, arising from a combination of immaturity of the newborn skin with environmental factors. Nonetheless, some of them may eventually be a clue to underlying disorders. Physicians should therefore be aware of these clinical manifestations so that parents can be reassured and, when necessary, complementary investigations can be undertaken.

Unilateral Koilonychia Secondary to Chemical Depilatory Product

Excess hair is a problem for both men and women who want to conform to today's cosmetic social norms. Chemical depilatories are a safe, fast, and inexpensive method of hair removal. The most commonly used depilatory agents are thioglycolates and to a lesser extent, sulphides. The most common side effect of chemical depilatories is irritant contact dermatitis. However, allergic contact dermatitis is rare and may be related to lanolin, fragrance, or thioglycolate itself. Unilateral koilonychia as a side effect of chemical depilatories has not been described previously in the literature. We report this case due to its rarity and highlight the significance of nail protection while using chemical depilatory products.

Dermatological manifestations in cardiofaciocutaneous syndrome: a prospective multicentric study of 45 mutation-positive patients

BACKGROUND

Data on dermatological manifestations of cardiofaciocutaneous syndrome (CFCS) remain heterogeneous and almost without expert dermatological classification.

OBJECTIVES

To describe the dermatological manifestations of CFCS; to compare them with the literature findings; to assess those discriminating CFCS from other RASopathies, including Noonan syndrome (NS) and Costello syndrome (CS); and to test for dermatological phenotype-genotype correlations.

METHODS

We performed a 4-year, large, prospective, multicentric, collaborative dermatological and genetic study.

RESULTS

Forty-five patients were enrolled. Hair abnormalities were ubiquitous, including scarcity or absence of eyebrows and wavy or curly hair in 73% and 69% of patients, respectively. Keratosis pilaris (KP), ulerythema ophryogenes (UO), palmoplantar hyperkeratosis (PPHK) and multiple melanocytic naevi (MMN; over 50 naevi) were noted in 82%, 44%, 27% and 29% of patients, respectively. Scarcity or absence of eyebrows, association of UO and PPHK, diffuse KP and MMN best differentiated CFCS from NS and CS. Oral acitretin may be highly beneficial for therapeutic management of PPHK, whereas treatment of UO by topical sirolimus 1% failed. No significant dermatological phenotype-genotype correlation was determined.

CONCLUSIONS

A thorough knowledge of CFCS skin manifestations would help in making a positive diagnosis and differentiating CFCS from CS and NS.

Spoon nails: still seen in today's world

Koilonychia is a nail abnormality characterized by thin, brittle, and spoon‐shaped nails. It is frequently observed in chronic iron deficiency secondary to malnutrition, chronic blood loss, or malabsorption. It may also be idiopathic or related to occupation and rare systemic disorders. Presence of koilonychia should prompt investigations for iron deficiency.

Nail Disorders in Children

Nail diseases in children do not account for a significant proportion of pediatric consultations, and most of the time the nails are not observed by the clinician, overlooking their importance. Specific examination of the nails is neglected, while localization to the nails could be an initial sign of a syndrome or a systemic disorder. Nail diseases in the pediatric population differ from those in adults in terms of diagnostic approach and management; some of them even are manifested mainly or exclusively in children. Pediatric patients with underlying systemic disorders are more likely to manifest acquired disorders of the nails. Although rare, nail diseases in children are a source of anxiety for the parents. Examination of the nails is an essential part of pediatric physical examination. A correct clinical history and careful examination help the clinician to distinguish the different conditions and to decide on the correct management of nail diseases in young patients. A classification of nail dystrophies according to age is somewhat arbitrary and a unique classification does not exist. Nail diseases in the pediatric population can be divided according to age groups where a predilection appears in most of the cases. Moreover, certain abnormalities may be lifelong once acquired, but their presentation may be modified by age, worsening or improving during life. This review describes many of the nail conditions that are seen in the pediatric population aging from newborn to toddler, starting with physiological aspects to better recognize the pathological conditions.