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Post-traumatic acquired polyonychia: A rare occurrence

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Post-traumatic acquired polyonychia: A rare occurrence
Nitin Ramchandra Lade MD, Divya Bimit Jain MBBS, Adarsh Lata Singh MD
Dermatology Online Journal 18 (6): 10

J N Medical College Wardha, Maharashtra, India


The majority of nail disorders are usually acquired; few are of congenital origin. Trauma to the nail unit commonly leads to dystrophy or deformity of the nail, but a division of the nail matrix can result in acquired polyonychia (split nail). Herein we describe a case of a 50-year-old male who had trauma in childhood after which he developed two nails on the right thumb. Cutaneous examination and X-ray revealed a well-defined split nail plate on the thumb. Surgery was advised but patient declined any surgical intervention. We describe this case for its rare occurrence.


The nail plate protects the nail bed and helps in fine movement and fine grasp [1]. Nail damage, whether congenital or acquired, may produce more cosmetic and psychological impact than functional impairment. Herein we describe a patient subjected to sharp trauma who developed a split nail.

Case report

Figure 1Figure 2
Figure 1. Right thumb showing polyonychia (split nail) with deep longitudinal groove.

Figure 2. X-ray of right thumb revealed two separate nail plates on the distal phalange.

A 50-year-old male presented with extra nail grown over the right thumb. He had history of trauma to the right thumb by a sharp stone at the age of 13. Since then he developed two nails. No other complaints were present. General and systemic examination was normal. Nail examination revealed two nail plates on the right thumb. The medial side nail measured 2 cm x 1.2 cm and the lateral one measured 2 cm x 1 cm with a deep longitudinal groove in the split nail plate (Figure 1). X-ray ofthe right thumb revealed two separate nail plates on the distal phalange (Figure 2). Other nails and cutaneous examination were normal except for an eczematous patch over the left ankle. The patient was advised surgical correction but he declined.


Acquired nail dystrophies are more common than the developmental disorders [1]. Congenital polonychia is seen in the Pieree Robin syndrome [2]. Trauma, infection, and eczema are the most common causes of onychodystrophy. Acute trauma commonly leads to splinter hemorrhages, subungual hematoma, and nail shedding [3]. Delayed effects of trauma are split ridges, pterygium, hook nail, pigment bands, and ectopic nails [4]. Split nail is the most common serious chronic deformity that occurs as a result of acute injury [5]. Sharp objects or surgical trauma can lead to division of nail matrix, which gives an acquired supernumerary nail. It can also result from longitudinal biopsy [5]. Spilt nails require surgical excision and revision of scar. Rarely the nail matrix splits cleanly to form a fully split nail, which resembles a supernumerary nail as seen in our patient. It may resemble a variety of developmental anomalies like congenital onychodysplasias [6, 7]. Our patient developed acquired polonychia secondary to sharp trauma.


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