Fingernail dystrophy in a young child

Trachyonychia, also known as "20-nail dystrophy," is an abnormal nail condition characterized by longitudinal ridging, pitting, fragility, thinning, distal notching, and opalescent discoloration that mostly affects children, but can occur in people of all ages.1,2 It can result as a...

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Trachyonychia, also known as “20-nail dystrophy,” is an abnormal nail condition characterized by longitudinal ridging, pitting, fragility, thinning, distal notching, and opalescent discoloration that mostly affects children, but can occur in people of all ages.^1,2 It can result as a manifestation of other dermatologic conditions or it can be idiopathic. Although determining the

Longitudinal striations of the nail can be seen as a normal part of the aging process, appearing as accentuated ridges over the nail surface. However, when nails lose their opalescence and begin thinning, a diagnosis of trachyonychia must be considered. When all of the nails are affected, the condition is referred to as 20-nail dystrophy.²

Trachyonychia is more common in children, often presenting with an insidious onset between the ages of 3 and 12 years, but cases have been reported in patients of all ages.^2,3 Associated conditions include alopecia areata, psoriasis, atopic dermatitis, and lichen planus. Alopecia areata has been the most commonly reported associated disease; an estimated 3.65% of patients have trachyonychia.⁴ Although the prevalence of idiopathic trachyonychia is unknown, it is likely more common than is reported in literature.⁵

Clinically, trachyonychia is described as having 2 varieties—shiny and opaque— corresponding to mild and severe versions, respectively. The mild type is characterized by shiny nails with superficial longitudinal ridging and diffuse, small pitting. Importantly, the nails retain their luster. In the severe type, nails appear opaque and sandpaper like, with excessive longitudinal ridging caused by fine, parallel-oriented superficial striations, and they have hyperkeratotic, irregular cuticles. In both the mild and severe variants, fingernails are affected more than toenails, and koilonychia is a common finding.³

The range of severity seen in trachyonychia can be attributed to the extent of inflammation that occurs in the nail matrix.^1,3 Severe and persistent inflammation results in nails showing diffuse damage and loss of luster, as seen in severe trachyonychia. Conversely, inflammation that is mild and intermittent results in multifocal damage and nails that retain their luster, as seen in milder variants of trachyonychia.

On biopsy, trachyonychia commonly shows generalized spongiosis and inflammatory cells in the nail epithelium.³ This is seen in patients with associated alopecia areata as well as idiopathic trachyonychia. In patients with associated lichen planus or psoriasis, histopathologic changes congruent with the associated disease are seen on nail biopsy, such as psoriasiform changes in patients with trachyonychia.³ Another histopathologic change seen in patients with trachyonychia is nail hypergranulosis. Inflammation and trauma to the nail matrix can result in increased expression of keratin granules in the nails. Although trachyonychia does not cause permanent scarring, hypergranulosis of the nail matrix may remain even after inflammation subsides.³

However, biopsy is generally not advised as the standard procedure for trachyonychia. Although trachyonychia rarely causes permanent nail damage, nail matrix punch and longitudinal nail biopsy can result in trauma and scarring. In both adult and pediatric cases reported in literature, the majority of patients report improvement over time regardless of treatment.^6,7

Differential diagnoses for trachyonychia include fungal infections, psoriasis, brittle nails, senile nails, lichen planus, psoriasis, eczematous nail changes, and nail changes of alopecia areata.^1,8 Eczema and fungal infections rarely cause observable disease in all the nails simultaneously. Brittle nails lack the pronounced ridging and roughness observed in trachyonychia.¹ Senile nails may show mild longitudinal ridging, but lack diffuse involvement of the entire nail plate.⁸ Similar superficial, geometric pitting can be seen in both alopecia areata and the shiny variant of trachyonychia.³ In lichen planus, nails can also have pitting and longitudinal streaks, but formation of pterygium is not seen in trachyonychia.⁹ In psoriasis, observable nail changes include pitting, onycholysis, salmon spots, oil spots, splinter hemorrhages, and subungual hyperkeratosis.¹⁰

No universally accepted standard treatment exists for trachyonychia. Treatment is mainly cosmetic because it is not a permanently scarring condition; most patients show resolution of symptoms regardless of treatment.^5,6 Intralesional steroids, topical PUVA, biotin (2.5 mg/d for 6 mo), and 5% 5-fluorouracil cream have been shown to cause improvement in select patient cases in the literature. In other patient cases, treatment with oral vitamin A and topical steroids under occlusion failed to show any changes in the patient’s disease.⁵ Ultimately, there is not a standardized guideline for the treatment of trachyonychia, and much of the published literature is aimed at targeting the underlying disorder, such as in psoriasis, lichen planus, and alopecia areata. Aside from treating an associated underlying condition, most cases are not treated and spontaneously resolve.

The patient in this case was diagnosed with trachyonychia of the fingernails. Her circular hair loss was diagnosed as alopecia areata and treated with a topical steroid solution. The patient was advised that no treatment was necessary for her nail findings and that her nails would likely normalize with time. In the meantime, she was advised that she could apply cosmetic nail polish to her nails to assist with cosmesis.

Simo Huang, BS, is a medical student at the Baylor College of Medicine, and Christopher Rizk, MD, is a dermatology resident at the Baylor College of Medicine.

References

1. Bolognia JL, Jorizzo JL, Rapini RP. Dermatology. St. Louis, MO: Mosby/Elsevier; 2008.
2. Scheinfeld NS. Trachyonychia: a case report and review of manifestations, associations, and treatments. Cutis. 2003;71:299-302.
3. Tosti A, Bardazzi F, Piraccini BM, Fanti PA. Idiopathic trachyonychia (twenty-nail dystrophy): a pathological study of 23 patients. Br J Dermatol. 1994;131:866-872.
4. Tosti A, Fanti PA, Morelli R, Bardazzi F. Trachyonychia associated with alopecia areata: a clinical and pathologic study. J Am Acad Dermatol. 1991;25(2 Pt 1):266-270.
5. Tosti A, Piraccini BM, Iorizzo M. Trachyonychia and related disorders: evaluation and treatment plans. Dermatol Ther. 2002;15:121-125.
6. Kumar MG, Ciliberto H, Bayliss SJ. Long-term follow-up of pediatric trachyonychia. Pediatr Dermatol. 2015;32:198-200.
7. Sakata S, Howard A, Tosti A, Sinclair R. Follow up of 12 patients with trachyonychia. Australas J Dermatol. 2006;47:166-168.
8. Singh G, Haneef NS, Uday A. Nail changes and disorders among the elderly. Indian J Dermatol Venereol Leprol. 2005;71:386-392.
9. Nakamura R, Broce AA, Palencia DP, Ortiz NI, Leverone A. Dermatoscopy of nail lichen planus. Int J Dermatol. 2013;52:684-687.
10. Nakamura RC, Costa MC. Dermatoscopic findings in the most frequent onychopathies: descriptive analysis of 500 cases. Int J Dermatol. 2012;51:483-485.