Acantholytic dyskeratotic epidermal nevus as a mosaic form of Darier's disease

Diagnosis and management of longitudinal erythronychia: A clinical review by an expert panel

Longitudinal erythronychia (LE) is defined as a longitudinal red band of the nail(s) and is classified as localized (involvement of 1 nail) or polydactylous (involvement of more than 1 nail). The differential diagnosis is distinct for these classifications. The etiologies of localized longitudinal erythronychia are most frequently benign subungual neoplasms and less often malignancies. Polydactylous longitudinal erythronychia is typically secondary to regional or systemic diseases, including lichen planus and Darier disease. LE is a common but underrecognized clinical finding. Increased dermatologist awareness of the clinical characteristics and differential diagnosis for LE is necessary given the possibility for malignancy and associated systemic disease. In this clinical review, the clinical features, differential diagnosis, evaluation, and management of LE are described.

Epidermal Nevi and Related Syndromes -- Part 1: Keratinocytic Nevi

Epidermal nevi are hamartomatous lesions derived from the epidermis and/or adnexal structures of the skin; they have traditionally been classified according to their morphology. New variants have been described in recent years and advances in genetics have contributed to better characterization of these lesions and an improved understanding of their relationship with certain extracutaneous manifestations. In the first part of this review article, we will look at nevi derived specifically from the epidermis and associated syndromes.

Polydactylous Transverse Erythronychia: Report of a Patient with Multiple Horizontal Red Bands Affecting the Fingernails

INTRODUCTION

Redness of the nail plate-erythronychia-is a common condition involving one or multiple digits. It may affect the entire nail or present as longitudinal red bands that extend from the proximal nail fold to the distal tip of the nail plate. Rarely, red bands may traverse the nail bed horizontally. Although erythronychia is often idiopathic, it has also been associated with amyloidosis, Darier's disease, lichen planus, and various other cutaneous conditions. We describe the clinical features of a 64-year-old Caucasian man who presented with transverse and longitudinal erythronychia affecting his fingernails. In addition, we review the classification of erythronychia and summarize the acute and chronic conditions that have been associated with this clinical finding.

METHODS

The features of a man with polydactylous transverse and longitudinal erythronychia are presented. In addition, PubMed was used to search the following terms: erythronychia, longitudinal erythronychia, red lunulae, and subungual. All papers were reviewed, and relevant articles, along with their references, were evaluated. Informed consent was obtained from the patient for being included in the study.

RESULTS

A 64-year-old Caucasian man with a past medical history significant for testicular cancer and pulmonary embolism presented with multiple horizontal pink-red bands affecting his fingernails. The discoloration was most prominent in the region distal to the lunula. In addition, the nails of the fifth digit of his left hand and third digit of his right hand featured longitudinal red bands extending from the distal curvature of the lunula to the free edge of the nail plate. A diagnosis of polydactylous longitudinal and transverse erythronychia, based on the clinical presentation, was established. Our patient's red bands were asymptomatic and he was not concerned about the cosmetic appearance of his nails; therefore, no additional investigation or treatment was required.

CONCLUSION

Polydactylous transverse erythronychia is a rare condition characterized by the development of horizontal red bands affecting the fingernails or toe nails. It has only been previously described in a man with multiple system atrophy. In our patient, both transverse and longitudinal red bands were present simultaneously. Therefore, it is possible that horizontal erythronychia is an early clinical manifestation of longitudinal erythronychia.

Nail abnormalities associated with systemic pathologies

Nail abnormalities can arise in conjunction with or as a result of systematic pathologies. These pathologies include single-organ diseases, multisystemic diseases, and drug-induced insults. Clinical signs associated with these conditions include dyschromias, vascular alterations, periungual tissue changes, textural dystrophies, contour alterations, and growth-rate alterations. The associated systemic pathologies may affect any part of the nail apparatus, including the nail matrix, the nail plate, the nail bed, the underlying vasculature, and the periungual tissues. The anatomical location and extent of damage determine the clinically manifested anomaly.

Longitudinal erythronychia: individual or multiple linear red bands of the nail plate: a review of clinical features and associated conditions

Longitudinal erythronychia is a linear red band on the nail plate that originates at the proximal nail fold, traverses the lunula, and extends to the free edge of the nail plate. Longitudinal erythronychia is classified based upon the number of nails affected and the number of red streaks present on each nail as follows: type Ia (monodactylous - single band), type Ib (monodactylous - bifid bands), type IIa (polydactylous - single band), and type IIb (polydactylous - multiple bands). Associated morphologic findings that can be present at the distal tip of the nail with longitudinal erythronychia include fragility, onycholysis, splinter hemorrhage, splitting, subungual keratosis, thinning, and V-shaped nick. Some patients with longitudinal erythronychia seek medical evaluation because of pain in the associated distal digit; however, the linear red nail plate dyschromia is often asymptomatic and the individual is concerned about the cosmetic appearance or distal nail fragility. Longitudinal erythronychia can be a clinical manifestation of an underlying local or systemic condition. Benign tumors (glomus tumor, onychopapilloma, and warty dyskeratoma), malignant neoplasms (malignant melanoma and squamous cell carcinoma), and other conditions (hemiplegia and postsurgical scar) can be associated with monodactylous longitudinal erythronychia or it may be idiopathic or the initial stage of polydactylous longitudinal erythronychia-associated systemic conditions. Polydactylous longitudinal erythronychia is most commonly reported in patients with Darier disease (keratosis follicularis); other associated conditions include acantholytic dyskeratotic epidermal nevus, acantholytic epidermolysis bullosa, acrokeratosis verruciformis of Hopf, amyloidosis, graft-versus-host disease, lichen planus, and pseudobulbar syndrome. Polydactylous longitudinal erythronychia has also been observed as an idiopathic finding. Biopsy of the nail matrix and nail bed may be necessary to establish the diagnosis of a longitudinal erythronychia-associated condition. Indeed, a biopsy should be seriously considered in patients aged more than 50 years who present with a monodactylous longitudinal red band to exclude squamous cell carcinoma. Treatment of longitudinal erythronychia depends on the etiology. For patients with longitudinal erythronychia-associated discomfort or severe nail splitting, a surgical excision may provide not only the underlying diagnosis of the nail dyschromia, but also relief of related symptoms.

A Japanese case of segmental Darier's disease caused by mosaicism for the ATP2A2 mutation

Darier's disease is an autosomal dominant skin disorder that is characterized by multiple keratotic papules, focal loss of adhesion and abnormal keratinization. Mutations in the ATP2A2 gene encoding sarco/endoplasmic reticulum calcium pumping ATPase type 2 have been identified as the molecular basis of Darier's disease. Segmental Darier's disease is a rare type of Darier's disease in which there is characteristic localization of the keratotic papules in a linear pattern following Blaschko's lines. In this study we examined ATP2A2 mutations in a Japanese patient with segmental Darier's disease. The samples from affected skin, unaffected skin and peripheral leucocytes were subjected to polymerase chain reaction (PCR). Direct sequencing of the PCR products was performed. Sequence analysis revealed that the patient had 160A-->G substitution mutation which predicts I54V. This novel mutation was present in the affected skin, but not in the unaffected skin or peripheral leucocytes. This is the first report of segmental Darier's disease caused by mosaicism for an ATP2A2 mutation in Japan.

Acantholytic dyskeratotic naevi following Blaschko's lines: a mosaic form of Darier's disease

Darier's disease (DD) is an autosomal-dominant skin disorder characterized by loss of adhesion between epidermal cells and abnormal keratinization. Several patients with unilateral, linear, 'zosteriform' or localized lesions have been reported. We report three cases of DD in a localized pattern corresponding to mosaicism type 1 according to Happle's classification and review the literature about the genetic cause of DD and DD in a 'zosteriform' pattern.

Mosaicism for ATP2A2 mutations causes segmental Darier's disease

Epidermal naevi are localized malformations of the epidermis consisting of verrucoid scaly papules and plaques following Blaschko's lines. Genetic mosaicism has been proposed to underlie the development of linear epidermal naevi. Rarely, epidermal naevi show acantholytic histology similar to Darier's disease, a dominantly inherited skin condition characterized by widespread warty papules. As patients with acantholytic dyskeratotic naevi often give a history of worsening after sun exposure and the lesions are typical of Darier's disease, numerous authors have proposed that these patients have segmental Darier's disease. The postulated relationship has not been proven, however. Recently, we identified ATP2A2, which encodes the sarco/endoplasmic reticulum Ca(2+) ATPase isoform 2 as the defective gene in Darier's disease. In this report, we investigated the involvement of ATP2A2 in acantholytic dyskeratotic naevi following Blaschko's lines in two patients. We identified a nonsense mutation (Y894X) in the first patient and a nonconservative glycine to arginine mutation at codon 769 (G769R) in the other patient. These mutations were present in affected skin, and were not detected in unaffected skin or in leukocytes. We conclude that acantholytic dyskeratotic naevi can arise from a somatic mutation in ATP2A2. These individuals are mosaics for the mutation, but the risk of transmission of generalized Darier's disease will depend on whether the germline is affected. Our findings provide further evidence that Blaschko's lines do reflect genetic mosaicism and that the term acantholytic dyskeratotic naevus might be replaced in the future by segmental Darier's disease induced by postzygotic mosaicism. J Invest Dermatol 115:1144-1147 2000

Epidermal naevus with Darier's disease-like changes in a patient with Gardner's syndrome

We describe the unique presentation of a linear epidermal nevus with histologic features of Darier's disease occurring in a patient with Gardner's syndrome. Classification of localized forms of Darier's disease as an epidermal nevus or as a genetic mosaicism remains controversial. The association of this disorder with Gardner's syndrome has not been described in the literature before.

Eosinophilic cellulitis following the lines of Blaschko

Eosinophilic cellulitis is an inflammatory dermatosis of unknown aetiology. We describe a case following the lines of Blaschko, which may be the expression of cutaneous mosaicism, suggesting a possible underlying genetic predisposition for the development of Wells' syndrome.

Acantholytic dyskeratotic epidermal nevus induced by ultraviolet B radiation

We report a case of acantholytic dyskeratotic epidermal nevus induced by repeated ultraviolet B radiation in a 16-year-old Korean girl. She had experienced pruritic skin rashes on the right side of the abdomen and flank area in a zosteriform distribution for the past 10 years. They were aggravated during the summer and spontaneously disappeared in the winter. Papules revealed acantholytic dyskeratotic cells that were diagnosed as acantholytic dyskeratotic epidermal nevus. Suberythemal and erythemal doses of UVB were irradiated to the lesional skin (right side of abdomen) and nonlesional skin (left side of abdomen) for 4 consecutive days. UVB-induced pruritic papules were observed on the lesional skin and a biopsy specimen of the papules also showed acantholytic dyskeratotic cells, which were compatible with acantholytic dyskeratotic epidermal nevus.

Acantholytic dyskeratotic epidermal naevus localized unilaterally in the cutaneous and genital areas

A 38-year-old woman presented with unilateral lesions on the left side of the body and in the genital area. Clinically, the lesions showed a polymorphic pattern: brownish papules in the axilla, keratotic comedo-like papules on the hand and foot, and whitish papular plaques on the labia majora and anal canal. There was no family history of skin diseases. Histologically, cutaneous and mucosal specimens were characterized by acantholytic and dyskeratotic cells, corps ronds and grains in the parakeratotic zone, and by hyperkeratosis and parakeratosis. A diagnosis of epidermal naevus with acantholytic dyskeratosis was made.

Frontoparietal scleroderma (en coup de sabre) following Blaschko's lines

We describe three patients with frontoparietal scleroderma showing multiple lesions. The lesions were in two different lines that seemed to belong to Blaschko's lines. It remains controversial whether linear scleroderma follows Blaschko's lines, but our observations presented here suggest that frontoparietal scleroderma occurs along the lines of Blaschko.