An 8-year-old boy presents to the clinic for evaluation of a progressively worsening nail dystrophy that began a few months ago. The patient’s mother denies a family history of skin diseases and reports that her son has no history of medical problems. On physical examination, all of the boy’s fingernails and toenails show hyperkeratosis, longitudinal ridging, loss of luster, and roughness. His hair, skin, and oral mucosa are unremarkable. Nail biopsy reveals spongiotic changes and exocytosis of inflammatory cells into the nail epithelia. The results of a fungal culture are negative.
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The term trachyonychia is derived from trakos, the Greek word for “rough nails.”1 The condition is a nail plate abnormality characterized by roughness, excessive longitudinal ridging, cuticle thickening, and brittleness of the distal nail. Defective keratinization of the proximal nail matrix causes the disease. Trachyonychia often is called “20 nail dystrophy,” but the phrase is falling out of favor because it does not accurately describe the condition,which may involve 1 or as many as 20 nails.2 The incidence of trachyonychia is not known, and it does not seem to show a predilection for either sex.2
Two types of trachyonychia are recognized: opaque and shiny.2 Opaque trachyonychia is more common and severe, presenting with rough, brittle, and longitudinally ridged nails. This type of trachyonychia often is referred to colloquially as “sandpaper nails” because the nails appear to have been rubbed with sandpaper. Shiny trachyonychia occurs less frequently and is characterized by uniform, opalescent nails with multiple small geometric pits.2 In both forms, fingernails are affected more commonly than toenails.
Histopathologic examination reveals differences between the 2 types of trachyonychia. The opaque type of trachyonychia shows inflammation that never ceases over the duration of the condition. Shiny-type trachyonychia demonstrates a waxing and waning pattern of abnormality punctuated by periods of normal nail matrix function.3
Trachyonychia occurs more commonly in children but can occur at any age.2 It may be idiopathic or associated with other dermatologic or nondermatologic conditions. The most common dermatologic diseases associated with trachyonychia are alopecia areata, lichen planus, and psoriasis.2 Alopecia areata, the disease most commonly associated with trachyonychia, is estimated to affect 3.65% of patients.4 Gordon et al describe trachyonychia as alopecia areata of the nails.1 Less commonly associated skin diseases include vitiligo, ichthyosis vulgaris, atopic dermatitis, and pemphigus vulgaris. Nondermatologic conditions associated with trachyonychia include immunoglobulin A deficiency, amyloidosis, and sarcoidosis.2
Histopathologic findings for trachyonychia often but not always match the associated skin disease.4-7 For example, patients with psoriasis and trachyonychia can demonstrate similar pathologic changes in the nails and skin, with findings of acanthosis, focal parakeratosis, and accumulation of polymorphonuclear cells along the dorsal nail plate.1 The majority of patients with idiopathic trachyonychia or trachyonychia associated with alopecia areata exhibit spongiotic changes and exocytosis of inflammatory cells into the nail epithelia on nail biopsy.4,5 However, there are reports of patients with alopecia areata demonstrating typical features of lichen planus on nail biopsy.4 Nail findings in patients with idiopathic trachyonychia also can include histologic findings common to lichen planus, psoriasis, and even pemphigus vulgaris.4,5
Trachyonychia is a clinical diagnosis, and nail biopsy, which can be invasive and cause scarring, is not indicated.1,7,8 When evaluating a patient with trachyonychia, health care practitioners should consider other causes of nail dystrophy in the differential diagnosis. A thorough personal and family history of skin disorders is recommended as well as careful examination of the skin, mucosa, and hair to evaluate for associated disorders.
Many features of trachyonychia overlap with those of other nail dermatoses. In particular, onychomycosis, brittle nails, and senile nails should be considered in the differential diagnosis of a patient with trachyonychia. Onychomycosis may be eliminated from the differential by confirmatory testing, including histology, fungal culture, or potassium hydroxide prep. Trachyonychia often is misdiagnosed as onychomycosis and, therefore, these tests are recommended before initiation of antifungal therapy.6 In patients with onychomycosis, brittle nails show superficial and longitudinal splitting but not the excess ridging and roughness seen in patients with trachyonychia.8 Senile nails show mild longitudinal ridging and beading, but these abnormalities are not diffuse and do not involve the entire nail plate.8
In most cases, trachyonychia improves spontaneously. The median duration of disease is 32.5 months in children and 77.0 months in adults.9 It is important to counsel patients on the benign nature of the disease and its generally good prognosis. However, patients may request treatment to improve the appearance of their nails. For patients with shiny trachyonychia, use of clear nail polish is a low-risk treatment option that may improve the appearance of the nails.2
In patients who have trachyonychia associated with an underlying disease, treatment of the associated disease is recommended.2 In patients without an associated disease, the recommended course is a trial period of observation followed by topical or systemic treatments.2 Topical treatments include tazarotene gel, 5-fluorouracil, corticosteroids, and psoralen plus ultraviolet A therapy. Systemic options include retinoids such as acitretin, corticosteroids, and antimalarial agents. Intralesional injection of triamcinolone into the proximal nail fold also has been shown to be effective.2 There is no standardized, evidence-based method of treatment.8 The age of the patient, the type and severity of trachyonychia, prior treatments, and associated diseases all should be taken into account when determining the best treatment regimen.2
In this case, the mother of the boy was reassured that the lesions may resolve over time and no treatment was prescribed.
Preeya Bhavsar, BS, and Emily Burns, BA, are medical students at Baylor College of Medicine, and Christopher Rizk, MD, is dermatologist affiliated with Elite Dermatology in Houston, Texas.
- Gordon KA, Vega JM, Tosti A. Trachyonychia: a comprehensive review. Indian J Dermatol, Venereol Leprol. 2011;77(6):640-645.
- Haber JS, Chairatchaneeboon M, Rubin AI. Trachyonychia: review and update on clinical aspects, histology, and therapy. Skin Appendage Disord. 2017;2(3-4):109-115.
- Tosti A, Bardazzi F, Piraccini BM, Fanti PA, Cameli N, Pileri S. Is trachyonychia, a variety of alopecia areata, limited to the nails? J Invest Dermatol. 1995;104(5 suppl):27S-28S.
- 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.
- Tosti A, Bardazzi F, Piraccini BM, Fanti PA. Idiopathic trachyonychia (twenty-nail dystrophy): a pathological study of 23 patients. Br J Dermatol. 1994;131(6):866-872.
- Chu DH, Rubin AI. Diagnosis and management of nail disorders in children. Pediatr Clin North Am. 2014;61(2):293-308.
- Grover C, Khandpur S, Reddy BS, Chaturvedi KU. Longitudinal nail biopsy: utility in 20-nail dystrophy. Dermatol Surg. 2003;29(11):1125-1129.
- Jacobsen AA, Tosti A. Trachyonychia and twenty-nail dystrophy: a comprehensive review and discussion of diagnostic accuracy. Skin Appendage Disord. 2016;2(1-2):7-13.
- Lee YB, Cheon MS, Park HJ, Cho BK. Clinical study of twenty-nail dystrophy in Korea. Int J Dermatol. 2012;51(6):677–681.