Indian Journal of Paediatric Dermatology

CASE REPORT
Year
: 2014  |  Volume : 15  |  Issue : 2  |  Page : 86--88

Benign pigmentation of nails


Biplab Maji, Sandipan Dhar 
 Departments of Pediatric Medicine and Pediatric Dermatology, Institute of Child Health, Kolkata, West Bengal, India

Correspondence Address:
Biplab Maji
Institute of Child Health, 11 Biresh Guha Street, Kolkata - 700 017, West Bengal
India

Abstract

Nail bed pigmentation or melanonychia is common in Blacks. Sometimes it is seen in Whites and Japanese, and may be associated with pigmentation of lips and oral mucosa, termed as Laugier-Hunziker (LH) syndrome. Nail pigmentation is usually in the form of longitudinal bands, sometimes with nail dystrophy, mostly acquired, and majority of the times associated with a family history. Here, we are reporting two cases of Indian origin with benign hyperpigmented nails, in which no possible cause was identified and there was no family history with such lesions.



How to cite this article:
Maji B, Dhar S. Benign pigmentation of nails.Indian J Paediatr Dermatol 2014;15:86-88


How to cite this URL:
Maji B, Dhar S. Benign pigmentation of nails. Indian J Paediatr Dermatol [serial online] 2014 [cited 2020 Dec 4 ];15:86-88
Available from: https://www.ijpd.in/text.asp?2014/15/2/86/139506


Full Text

 INTRODUCTION



Melanocytic activation or melanocytic stimulation or functional melanonychia is the process by which melanonychia results from increased melanic pigmentation of the nail matrix epithelium and nail plate without a concurrent increase in the number of melanocytes. [1] Seventy-three percent of single-digit longitudinal melanonychia (LM) occurs as a result of melanocytic activation. [1],[2] Blacks, Asians, Hispanics, and Middle Easterners frequently have benign longitudinal pigmented bands. [1],[3] The number and width of the bands increase with age. [1],[4] Melanonychia, or melanin-derived brown-to-black nail pigmentation, is a diagnostic challenge for clinicians. The most serious disease of the nail unit, melanoma, primarily presents with melanonychia.

 CASE REPORTs



Case 1

An 8-year-old male presented with gradually progressive pigmentation of the nail of all four limbs, starting from the upper limb [Figure 1] and gradually involving the lower limbs [Figure 2] for last 4 years. The pigmentation was asymptomatic and not preceded by any inflammatory lesion. There was no pigmentation of the oral mucosa and/or any other abnormal pigmented lesion anywhere in the body. The patient was otherwise well and not on any medication. There was no family history of similar lesions, any oral mucosal or lip pigmentation, or polyposis. All the finger nails and toe nails were diffusely pigmented without discrete band appearance. Blackish discoloration spread onto the proximal nail folds from all the nails. Knuckles were not darkly pigmented as compared to the nails. No pitting or any history of any inflammation or injury to the nail was recognized. The palms, soles, and genitals were without any abnormal pigmentation. The genital and conjunctival mucosae were normal without any pigmentary changes. There was no lymphadenopathy. A systemic examination including per rectal and proctoscopic examination found no significant anomaly. Investigations revealed normal blood counts, renal and hepatic functions, and urinary findings. The results of stool guaiac test were negative. Sigmoidoscopy and colonoscopy did not reveal any abnormality. Histopathologic examination from the base of the nail of the left great toe was non-specific and revealed marked hyperkeratosis, hypergranulosis with flattening of the rete ridges, and increased melanin pigmentation in the basal layer.{Figure 1}{Figure 2}

After excluding Peutz-Jeghers syndrome, Addison's disease, Albright syndrome, lichen planus, drugs, and cyanocobalamine deficiency, we called it benign, but the term "familial" was not used because no other family member was affected. Though Laugier-Hunziker (LH) syndrome may not present with its typical features all the time, still we did not mark it as LH syndrome because of the atypical presentation of our case and lack of certainty of this diagnosis.

Case 2

A 6-year-old Indian male child reported with the development of blackish bands over nail plates of the ring finger of left hand and multiple parallel blackish bands over the middle finger of right hand [Figure 3], over the last 9 months. Because of fear of malignancy, he was referred by his primary physician to our outpatient clinic for a nail biopsy. Clinically, the black bands were wider at the proximal nail matrix and narrower at the distal nail plate. Apart from fear of malignancy and concern about the cosmetic appearance, the patient reported no other symptoms. No other nails of any other finger or toe were affected and there was no abnormal mucosal pigmentation. He was having no family history of such type of abnormal pigmentation. The patient was counseled about the benign nature of the condition and the pigmentation remained the same as before in 3 years of follow-up.{Figure 3}

 DISCUSSION



Melanonychia is brown or black pigmentation of the nail unit. Various causes such as physiologic longitudinal melanonychia, systemic disorders, trauma, inflammatory disorders, fungal infections, drugs, benign melanocytic hyperplasia, etc., are responsible for this condition, and most of them are benign. Chronic inflammatory conditions like onychomycosis, paronychia, psoriasis, lichen planus, amyloidosis, and chronic radio dermatitis may lead to the activation of melanocytes and the subsequent appearance of a light-brown band. [1] Possibility of onychotillomania, nail biting, frictional trauma, and even carpal tunnel syndrome should be explored [1],[5] because these are associated with melanonychia. Certain diseases like Addison's disease, Albright syndrome, lichen planus, drugs, cyanocobalamine deficiency, and AIDS are commonly accompanied by cutaneous and mucosal pigmentation. [1],[6] Medications (especially chemotherapeutic agents), [7],[8] phototherapy, X-ray exposure, and electron beam therapy [1],[9] Are the important causes of iatrogenically induced melanonychia. Syndrome-associated melanonychia, which occurs in conjunction with Laugier-Hunziker, Peutz-Jeghers, and Touraine syndromes, typically involves multiple digits, and also mucosal pigmented macules involving the lips and oral cavity. [1] LH syndrome is a chronic benign mucocutaneous syndrome that generally arises spontaneously in Caucasian adults in their 3 rd or 4 th decade, while Peutz-Jeghers and Touraine syndromes are autosomal dominant inherited disorders that typically manifest during childhood and are associated with intestinal polyposis, and there is an increased risk for gastrointestinal and pancreatic malignancies.

Melanonychia can be the initial "red-flag" sign in a large percentage of nail melanomas. So, a careful history and physical examination is mandatory. Dermatoscopy is able to differentiate between pigmented changes in the skin, but in most cases of nail pigmentation, this technique does not offer much help. In all cases, the possibility of initial melanoma should be considered, and in uncertain cases, nail biopsy and histological examination should be performed. Nail apparatus melanoma should be suspected in any patient with unexplained melanonychia who provides a history consisting of any of the following features: (i) Involvement of a single digit (especially the thumb, index finger, or great toe); (ii) development during the fourth decade of life or later; (iii) development in the setting of history of digital trauma; (iv) development in the setting of personal/family history of melanoma or dysplastic nevus syndrome; (v) development in the setting of nail dystrophy; and (vi) abrupt development or change (darkening or widening proximally). [10]

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