Clinical and Dermoscopic Features of Habit-Tic Nail Deformity: A Case Series

Dear Editor, Habit-tic nail deformity is an acquired nail dystrophy caused by repeated trauma to the nail matrix, usually from habitual rubbing or picking of the proximal nail fold. It most often affects the thumbnails and less frequently the toenails, and presents with a characteristic central longitudinal groove, transverse ridges and ragged or absent cuticle.[1] We present a case series of four patients highlighting the clinical and dermoscopic spectrum of this condition. A 12-year-old boy presented with roughness and splitting of both thumbnails for one year, with examination revealing a central longitudinal depression, transverse ridges, absent cuticle and thickened hyperpigmented proximal nail fold. He admitted pressing and picking at the nail fold [Figure 1a]. An 18-year-old boy with a 4-year history of bilateral thumbnail deformity showed a deep central depression with transverse ridges, destroyed cuticle and thickened proximal nail fold; though denying trauma, he was observed rubbing his nail against his index finger during consultation [Figure 1b]. A 24-year-old male reported 3 years of bilateral thumbnail changes, more marked on the right side, with central split, ridging, proximal nail fold pigmentation and cuticular damage; he acknowledged stress-induced rubbing of the nail fold [Figure 1c]. A 16-year-old boy presented with deformity of both great toenails for three years, showing transverse ridging and a central furrow; he reported tight footwear use and habitual rubbing of toes inside shoes [Figure 1d]. Dermoscopic examination across these cases revealed periungual scaling, absent cuticle, enlarged or pyramid-shaped lunula, splinter haemorrhages, transverse grooves, and longitudinal midline furrows [Figure 2a-d]. Direct microscopy with KOH mount and fungal culture excluded onychomycosis, confirming habit-tic deformity. Management included protective taping, frequent white soft paraffin application, behavioural counselling and psychiatric referral to rule out comorbid anxiety, depression or obsessive-compulsive disorder; additionally, the patient with toenail involvement was advised to wear socks and loose footwear. Habit-tic deformity is a variant of onychotillomania resulting from conscious or unconscious repetitive trauma to the nail fold. The classic “washboard” appearance, consisting of central groove with transverse ridging and loss of cuticle, remains the hallmark,[2] but dermoscopy is increasingly valuable in identifying subtle features such as macrolunula, microhemorrhages and branching grooves that enhance diagnostic confidence.[3] The most important differential diagnosis is median canaliform nail dystrophy of Heller, which presents with a midline nail split and oblique ridges but retains an intact cuticle.[4] Some authors regard both conditions as part of a single spectrum of repetitive nail matrix injury.[5] Early diagnosis is crucial to prevent chronic matrix damage, and management requires not only topical or protective measures but also psychiatric evaluation and behavioural therapy, underscoring the psychosomatic interplay in this deceptively simple-appearing nail disorder.Figure 1: (a and b) Bilateral habit-tic nail deformity presenting with absent cuticles, hyperpigmentation of the proximal nail folds, enlarged lunulae, and transverse grooves on both thumbnails with median depression extending from the proximal nail fold to the distal edge of the nail. (c) Bilateral involvement of the thumbnails, with more prominent changes on the right. The nails show a characteristic washboard appearance with median depression and transverse grooves. (d) Bilateral great toenail involvement showing features of habit-tic deformityFigure 2: (a and d) Dermoscopic examination (Heine delta 30, ×10, polarised mode), (a-d) Transverse furrows (red arrows); (a-c) longitudinal furrows (purple arrows); (b) splinter haemorrhages (yellow arrow); (a-d) macrolunula (blue arrows); (b and c) periungual scales (green arrows); (c) loss of cuticle (white arrow) and (a-c) scaling on the nail plate (black arrows)Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.