Nail lichen striatus: report of seven cases and review of the literature

Nail disorders to be kept in mind

Recognizing and diagnosing the most common nail diseases is essential, to be able to guide patients and provide appropriate treatment. However, uncommon nail disorders should not be neglected, in order to avoid inadequate treatment and above all to ensure that no severe underlying disorder, with severe prognosis, is overlooked.

Causes of longitudinal nail splitting: a retrospective 56-case series with clinical pathological correlation

BACKGROUND

Split nail (SN) is a rare type of nail fragility syndrome, characterized by a longitudinal fissure involving the entire thickness of the nail plate. Longitudinal nail splitting may be caused by direct injury to the nail plate or matrix insult. Few articles have been published on the topic, most were related to the traumatic aetiology. Some case reports mention tumours and inflammatory disorders as other causes.

OBJECTIVES AND METHODS

The aim of this retrospective study was to analyse the clinical and histopathological features of 56 SN collected at the nail consultation of the dermatology department at Saint Pierre University Hospital in Brussels, between 1997 and 2019.

RESULTS

Fifty-six patients were included (34 women and 22 men) with median age of 44.2 years. The fingernails were 3.2 times more frequently affected than toenails, especially the thumb. The most frequent aetiologies were tumours (45.6%), inflammatory diseases (26.3%) and traumas (19.3%). Congenital (5.3%) and systemic disorders (3.5%) were rarer causes. Histopathological slide review confirmed that alteration of the nail matrix integrity causes split nail, resulting either from matrix stretching by an underlying tumour or from impairment of the keratinization process by inflammatory diseases, melanocytic tumours and Bowen's disease.

CONCLUSIONS

This study is the largest case series of longitudinal nail splitting to date. It is the first to gather nail disorders causing SN with their clinical pathological correlation. The most common causes are traumatisms, tumours and inflammatory disorders. Congenital and systemic disorders are rarer. Tumours are responsible for half of the cases from which one third are malignant, mainly melanoma. When facing a monodactylic SN, benign as well as malignant tumours should be ruled out before concluding to traumatic aetiology.

Pathology of the Nail Unit

This article discusses the histologic findings in key nail unit diseases, including inflammatory, infectious, and neoplastic conditions. The emphasis is on clinicopathologic correlates, best practices to demonstrate the relevant histopathologic features, and pitfalls in diagnosis. Understanding the pathology of these disorders enhances clinical acumen and may affect the choice of biopsy procedures and treatment measures, with the outcome of better clinical care for patients with nail disease.

Pediatric nail disorders: a review

PURPOSE OF REVIEW

Nail disorders represent an uncommon subset of complaints seen in pediatric dermatology. There is a wide array of disorders that can affect the nail unit in children, including infectious, inflammatory, neoplastic, congenital, and traumatic processes. In order to enhance familiarity with pediatric nail conditions, we review the background and treatment of the more common entities seen in pediatric onychology, including onychomycosis, onychomadesis, nail psoriasis, trachyonychia, longitudinal melanonychia, onychophagia, and onychocryptosis.

RECENT FINDINGS

Nail involvement in pediatric patients with psoriasis may indicate increased risk for both overall disease severity and the development psoriatic arthritis. In the evaluation of longitudinal melanonychia, the clinical findings that raise concern for subungual melanoma in adults are often found in benign nail unit nevi in children. In the systemic treatment of pediatric onychomycosis, new data raises the possibility that laboratory monitoring may be approached differently. In the approach to onychophagia, emerging pharmacotherapies include N-acetylcysteine.

SUMMARY

Most nail disorders in pediatric patients have an overall favorable prognosis. However, nail abnormalities can lead to patient and parental anxiety, decreased quality of life, pain, and functional impairment. Clinicians should be aware of these more common diverse entities in order to identify them and apply state of the art management for these issues. Additionally, the reader will learn factors related to these nail disorders, which may require systemic work-up and/or specialist referral.

Lichen Striatus with Nail Involvement in a 6-Year-Old Boy

We describe a 6-year-old boy with an asymptomatic linear eruption on the left index finger with mild erythema of the proximal nail fold, nail dystrophy, and subungual hyperkeratosis of the nail. A diagnosis of nail lichen striatus was made. The child was successfully treated with a topical corticosteroid. Because of its rarity, nail lichen striatus is often under-recognized. Physicians should be familiar with the nail involvement in individuals with lichen striatus so that an accurate diagnosis can be made and unnecessary investigations and treatment avoided.

Pathogenesis, Clinical Signs and Treatment Recommendations in Brittle Nails: A Review

Nail plate brittleness (or fragility) is a common complaint affecting up to 20% of the population, especially women over 50 years of age, with fingernail fragility being more prevalent than toenail fragility. Nail brittleness is characterized by nails that split, flake and crumble, become soft and lose elasticity. The main clinical presentations are: onychoschizia, onychorrhexis, superficial granulation of keratin and worn-down nails. According to causative factors, we can distinguish 2 forms of nail fragility (NF): a primary "idiopathic or brittle nail syndrome" form and NF secondary to different causes such as inflammatory nail disorders, infections, systemic diseases and general conditions, traumas and alteration of the nail hydration. Optimal management requires treatment of the primary cause of brittle nails, when possible. In idiopathic NF oral supplementation, vitamins (especially biotin, also known as vitamin B7), trace elements and amino acids (especially cysteine) have been reported to be useful. In addition, several products, such as topical moisturizers and lacquers could be considered to restructure the affected nail plate and to reduce psychological impacts of this common problem.

Nail lichen striatus: Is dermoscopy useful for the diagnosis?

BACKGROUND/OBJECTIVES

Lichen striatus is a unilateral inflammatory dermatosis that rarely affects the nail unit. When the inflammation involves the nail unit, classic lichenoid nail changes are easily detectable, more often limited to only one portion of the nail. Usually the nail dystrophy coexists with periungual skin papules following Blaschko's lines, but it could also be an isolated feature. Because a nail unit biopsy presents difficulties in execution, especially in a child, the aim of our study has been to describe the nail unit dermoscopy features of lichen striatus hoping to provide a valid aid to clinicians in the diagnosing this rare disorder.

METHODS

We reviewed the images of five pediatric patients with a clinical diagnosis of lichen striatus. Data about sex, age, localization, predisposing/triggering factors, and associated disorders are reported.

RESULTS

The diagnosis of lichen striatus can be challenging as there are clinically overlapping features with related dermatoses. A common diagnostic pitfall occurs with inflammatory linear verrucous epidermal nevus and lichen planus. Involvement of only one part of the nail plate with linear longitudinal fissuring, ridging, and distal splitting, especially if seen with perionychial skin lesions, is characteristic of lichen striatus.

CONCLUSIONS

Nail lichen striatus is rare, and there is sparse published literature on it. When the changes in lichen striatus are limited to the nail, the diagnosis may easily be missed. We therefore believe that dermoscopy is an important diagnostic maneuver, which should be integrated into the evaluation of patients with potential lichen striatus, and in particular is helpful for clinicians unwilling or unable to perform a nail unit biopsy.

[Lichen nitidus and lichen striatus]

Lichen nitidus is a rare, chronic dermatosis which occurs more often in children than in adults. It presents with tiny, monomorphous, lichenoid, mostly asymptomatic papules in regional or disseminated distribution which show a pathognomonic histological pattern. The pathogenesis is unclear; however, immunologic phenomena and genetic factors are under discussion. In rare cases, an association with other dermatoses and systemic diseases has been described. Moreover, medical treatments have been incriminated as triggers. Considering the self-limited course in mostly young patients, treatment must be thoroughly weighed. Possible therapeutic options include topical corticosteroids and calcineurin inhibitors as well as oral antihistamines, corticosteroids and narrow-band ultraviolet B phototherapy. Lichen striatus is an acquired, usually asymptomatic dermatosis occurring mostly in preschool children. The characteristic feature is the arrangement of small, flat, light red- to skin-colored papules along the lines of Blaschko. Therefore, a postzygotic mutation of epidermal progenitor cells induced to express new surface antigens by trigger factors as infections, vaccinations or trauma with consecutive immune reaction is assumed. Nail involvement of the affected limb can rarely occur. Lichen striatus usually heals without scarring within several months, so that therapies with severe side effects are obsolete. Mild topical corticosteroids or calcineurin inhibitors may be used, especially if patients exceptionally suffer from pruritus. A postinflammatory hypopigmentation can persist for months to years.

Intramatricial platelet-rich plasma therapy: A novel treatment modality in refractory nail disorders

Two patients, one with nail lichen striatus and second with idiopathic trachyonychia were treated with intramatriceal injections of platelet-rich plasma. A total of 0.1 ml of the plasma solution was injected into the matrix of the involved nails at three weekly intervals. Follow-up was done at each sitting and thereafter at 16 and 20 weeks. Assessment was done both photographically and by dermoscopy. Case 1 showed marked improvement within 3 weeks and Case 2 showed improvement within 6 weeks. No relapses were seen at 16 and 20 weeks of follow up. Intramatricial PRP is a safe and effective therapeutic modality in nail lichen striatus and idiopathic trachyonychia refractory to other treatment options. Further studies with larger sample size and controls are required to validate the results.

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.