Characterization of nail matrix melanocytes with anti-PEP1, anti-PEP8, TMH-1, and HMB-45 antibodies

BACKGROUND

The normal nail matrix contains quiescent melanocytes with a peculiar arrangement and behavior.

OBJECTIVE

Our purpose was to identify nail matrix melanocytes with antibodies that recognize melanocytic cells in tissue sections.

METHODS

We used the polyclonal antibodies anti-PEP1 and anti-PEP8 and the monoclonal antibody TMH-1, which recognize melanocytic enzymes, and the monoclonal antibody HMB-45, which reacts with melanoma cells and fetal melanocytes, but not with normal adult melanocytes. Nail matrix specimens were obtained from longitudinal specimens of eight white patients with ingrown toenails. Specimens from normal adult forearm skin were used as controls.

RESULTS

All nail specimens gave similar results. Dendritic melanocytes were more numerous in the distal than in the proximal nail matrix. They were not restricted to the basal layer, but were also found in the suprabasal layers of the nail matrix epithelium. Melanocytes were seen both a single dendritic cells among the nail matrix keratinocytes and as small clusters that appeared irregularly distributed along the length of the nail matrix. Each cluster usually consisted of three to four cells.

CONCLUSION

Even if normally quiescent, nail matrix melanocytes possess the key enzymes responsible for the formation of melanin. The suprabasal location of nail matrix melanocytes may be a consequence of the distribution of adhesion molecules in the nail epithelium. In fact, in the nail matrix alpha 2, alpha 3, and beta 1 integrins are not only expressed on the basal, but also on the fourth to fifth suprabasal layers, with suprabasal expression gradually decreasing from distal to proximal matrix. The behavior of nail matrix keratinocytes may cause the peculiar arrangement and behavior of nail matrix melanocytes.

Drug-induced hair loss and hair growth. Incidence, management and avoidance

A large number of drugs may interfere with the hair cycle and produce hair loss. Drugs may affect anagen follicles through 2 main different modalities: (i) by inducing an abrupt cessation of mitotic activity in rapidly dividing hair matrix cells (anagen effluvium) or (ii) by precipitating the follicles into premature rest (telogen effluvium). In anagen effluvium, hair loss usually occurs within days to weeks of drug administration, whereas in telogen effluvium, hair loss becomes evident 2 to 4 months after starting treatment. Anagen effluvium is a prominent adverse effect of antineoplastic agents, which cause acute damage of rapidly dividing hair matrix cells. Telogen effluvium may be a consequence of a large number of drugs including anticoagulants, retinol (vitamin A) and its derivatives, interferons and antihyperlipidaemic drugs. Drug-induced hair loss is usually reversible after interruption of treatment. The prevalence and severity of alopecia depend on the drug as well as on individual predisposition. Some drugs produce hair loss in most patients receiving appropriate dosages while other drugs are only occasionally responsible for hair abnormalities. Both hirsutism and hypertrichosis may be associated with drug administration. Drugs most commonly responsible for the development of hirsutism include testosterone, danazol, corticotrophin (ACTH), metyrapone, anabolic steroids and glucocorticoids. Hypertrichosis is a common adverse effect of cyclosporin, minoxidil and diazoxide.

Hallopeau's acrodermatitis continua of the nail apparatus: a clinical and pathological study of 20 patients

The clinical diagnosis of Hallopeau's acrodermatitis (HA) restricted to nail and digital pulp may be difficult, and even dermatologists often fail to recognize this condition. The aim of this study was to review the clinical and pathological features of 20 patients, observed over a period of 5 years (1988-1993), who were affected by HA limited to the nails. Our study shows that HA of the nail unit more commonly affects middle-aged females. In all our patients HA of the nail was restricted to one digit and not associated with other manifestations of pustular psoriasis. HA of the nail unit is characterized by a chronic course. None of our patients had a complete clearing of the dermatitis during the follow-up period. In 4 patients the acute phases of HA were treated with the non-steroidal anti-inflammatory agent nimesulide 200 mg/day, with great improvement of inflammatory signs and subjective pain within a few days. In these patients, prolongation of treatment with nimesulide during remission phases prevented relapses of the dermatitis.

Nail lichen planus: clinical and pathologic study of twenty-four patients

BACKGROUND

We studied a large series of patients with lichen planus (LP) limited to the nails.

OBJECTIVE

Our purpose was to review the clinical and histopathologic features of 24 patients with LP limited to the nails and to discuss treatment and long-term prognosis.

METHODS

The records of 24 patients with biopsy-confirmed nail LP were analyzed. Clinical and follow-up data were obtained.

RESULTS

Nail LP usually appears during the fifth or sixth decade of life. Neither gender-associated susceptibility nor seasonal influences were detected. In most cases, nail LP is self-limiting or promptly regresses with treatment. Recurrences of nail lesions as well as development of LP in other regions of the body are possible. The development of severe and early destruction of the nail matrix characterizes a small subset of patients with nail LP.

CONCLUSION

Approximately 25% of patients with nail LP have LP in other sites before or after the onset of nail lesions. Long-term observation indicates that permanent damage to the nail is rare even in patients with diffuse involvement of the matrix.

Lichen planus limited to the nails in childhood: case report and literature review

Although nail abnormalities have been reported to occur in 1% to 10% of patients with lichen planus, in children with lichen planus they are rarely mentioned in the literature. An 11-year-old boy had a two-month history of nail dystrophy affecting all the fingernails and the great toenails. The nail plates showed longitudinal ridging and thinning as well as onycholysis and distal splitting. There were no cutaneous or mucous membrane abnormalities. A nail biopsy specimen showed hyperkeratosis, hypergranulosis, and acanthosis in the ventral portion of the proximal nail fold and in the nail matrix. A band-like lymphocytic infiltrate was present in the superficial dermis, and the basal layer showed vacuolar alterations. A diagnosis of lichen planus was made. Treatment was intramuscular triamcinolone 20 mg once a month for six months. Since 1969 only 13 proved pediatric cases of lichen planus limited to the nails have been reported, including two children with 20-nail dystrophy and four with idiopathic atrophy of the nails.

Atrichia and papular lesions: report of a case

We report a case of atrichia with papular lesions in a 4-year-old girl. The scalp was completely hairless since birth, except for dark, shiny, coarse hair on the frontoparietal region. Eyelashes and eyebrows were sparse. Numerous papular lesions developed on the hairless scalp, cheeks and neck during the second year of life. Teeth and sweating function were normal. The family history was negative. Histologic examination of a papular lesion showed the presence of a keratin-filled cyst in contact with the overlying epidermis. The pathology of the bald scalp showed the presence of tubular epithelial structures devoid of hair bulbs extending from the epidermis to the deep dermis and the superficial hypodermis. Sebaceous and outer root sheath differentiation was evident in most of the tubular structures that also frequently contained small ducts surrounded by two or three layers of flat epithelial cells. The superficial dermis contained horny cysts, similar to those present on the cheeks.