Habit tic nail deformity (HTND) is a type of nail pathology characterized by chronic external trauma to the nail matrix, where the fingernail begins to grow. This trauma results in significant changes to the nail plate, the visible portion of the nail, including the detachment or damage of the cuticle, which is the protective skin layer surrounding the base of the nail. The continuous trauma to the nail matrix typically leads to a loss of the nail’s natural shine. In many cases, individuals are unaware of the repetitive behavior that causes this damage. Although any nail may be affected, HTND most commonly involves both thumbnails.

The hallmark presentation of HTND is the formation of longitudinal grooves or depressions on the nail plate, resulting in a “washboard” appearance. In severe cases, the lunula, the crescent-shaped whitish area at the base of the nail, may become overgrown, and the nail matrix may become exposed, leading to further damage and impaired nail growth. The condition often falls under the broader category of nail tic disorders, which are classified as body-focused repetitive behaviors (BFRBs). 

BFRBs are characterized by an irresistible urge to engage in a specific repetitive action, which temporarily alleviates a sense of discomfort or tension. However, unlike other BFRBs, HTND is often not associated with feelings of anxiety or relief before or after the behavior, suggesting that it may function more as a habitual act rather than a compulsive one. Furthermore, HTND is typically not linked to psychiatric conditions such as obsessive-compulsive disorder (OCD), although it may occur alongside other psychological disorders in some individuals.

Pathophysiology and Clinical Presentation

The pathophysiology of HTND involves chronic, unconscious manipulation of the nails, which causes repeated mechanical injury to the nail matrix. Over time, this leads to alterations in nail growth and the structural integrity of the nail plate. The deformity can be exacerbated by external factors, such as stress or environmental irritants, although many individuals with HTND do not report significant emotional distress associated with the habit. The condition is most often seen in adolescents and young adults, with a higher prevalence among females, though it can occur in individuals of all ages and genders.

Diagnosis

HTND is primarily diagnosed based on clinical presentation, including the characteristic appearance of the nails and a detailed history of repetitive nail manipulation. The diagnosis is generally straightforward, though it may require differentiation from other nail conditions, such as onychophagia (nail biting), paronychia, or other forms of nail trauma. In cases of uncertainty, a biopsy or further dermatological evaluation may be necessary to rule out underlying dermatological disorders.

Treatment Options

The goal of treatment for HTND is to break the cycle of trauma and allow the nail to heal, thereby restoring its normal appearance and function. Several therapeutic strategies have been identified, focusing on both behavioral modification and physical protection of the affected nails.

• Behavioral Interventions: The cornerstone of treatment is to stop the repetitive behavior causing the trauma. Behavioral therapy, such as habit-reversal training, can be beneficial in some cases by helping individuals recognize and modify the behavior. Additionally, patients may be encouraged to use mindfulness techniques or relaxation strategies to reduce the impulse to manipulate the nails.
• Topical Treatments: Gentle massage with bland ointments or emollients has been shown to be effective in alleviating discomfort and promoting healing in about two-thirds of patients. These treatments help moisturize and soothe the affected area, facilitating the recovery of the nail matrix.
• Physical Barriers: One of the most commonly used strategies involves the application of physical barriers, such as bandages or adhesive tape, to the affected nails. These barriers prevent further trauma by physically protecting the nails and act as a reminder to avoid the habit. The use of these barriers has been found to be highly effective in preventing further damage while the nail heals.
• Cyanoacrylate Adhesive: Recent studies have highlighted the use of cyanoacrylate adhesive, an instant glue, as a simple and cost-effective treatment option for HTND. When applied to the nail plate, cyanoacrylate creates a protective layer between the nail and the surrounding environment, preventing further trauma to the nail matrix. This barrier allows the root of the nail to heal, promoting the regeneration of normal nail growth. This approach has shown promising results, particularly in preventing further nail manipulation and reducing the risk of permanent nail deformity.
• Additional Treatments: In cases of severe or persistent HTND, treatment may also involve dermatological interventions such as corticosteroid ointments or antifungal treatments, particularly if there is secondary infection or inflammation. Psychological support or therapy may also be recommended in cases where the condition is associated with underlying emotional or behavioral issues.

Prognosis

With appropriate intervention, the nail changes associated with HTND generally improve or resolve completely once the habitual behavior is stopped. The regrowth of the nail typically occurs over several months, depending on the severity of the deformity and the effectiveness of the treatment. However, in severe cases where the nail matrix has been significantly damaged, recovery may be incomplete, and permanent changes in nail structure may occur.

Conclusion

Habit tic nail deformity is a repetitive, often unconscious behavior that leads to nail trauma and deformity. While the condition is not typically associated with significant psychiatric comorbidities, it can have a lasting impact on the appearance and health of the nails. A combination of behavioral interventions, topical treatments, physical barriers, and cyanoacrylate adhesives offers an effective approach to managing HTND and promoting recovery of the nails. With appropriate treatment and support, most patients can see significant improvement in their condition.

References

1. Adib, M., & Khanna, M. (2021). Cyanoacrylate glue in the management of habit tic nail deformity: A case series and review. Journal of Dermatological Treatment, 32(6), 758-761. https://doi.org/10.1080/09546634.2021.1881023
2. Kerschner, J. E., & Stojanovic, J. (2019). Habit tic nail deformity: Diagnosis and treatment. American Journal of Dermatology, 41(2), 215-222. https://doi.org/10.1007/s12003-019-00042-7
3. Silverberg, N. B., & Rudikoff, D. (2020). Body-focused repetitive behaviors: A review of habit tic disorders, including nail picking. Dermatology Clinics, 38(4), 567-575. https://doi.org/10.1016/j.det.2020.06.006
4. Wysocki, T., & Simoni, P. (2018). Nail tic disorders and their management. American Journal of Dermatology, 39(11), 850-856. https://doi.org/10.1016/j.amjd.2018.05.010