Background
Brittle nail syndrome is described as a constellation of nail abnormalities including onychorrhexis and/or onychoschizia that collectively contribute to increased fragility of the nail plate. [1, 2] Onychorrhexis is classically characterized by longitudinal ridging of the nail. [1] It has been cited as the ungual alteration most associated with patient perception of nail fragility. [3] Onychoschizia refers to lamellar splitting of the distal free edge portion of the nail plate. [4, 5] It may also include breaks of the lateral edges causing transverse splitting. [1] The diagnosis of brittle nail syndrome is established based on patient history and physical examination findings.
Images of onychorrhexis and onychoschizia are shown below.
Brittle nail syndrome: Significant longitudinal ridging of the L1 and R1 fingernails in an otherwise healthy 77-year-old woman, consistent with onychorrhexis stage 3 ridging per grading criteria proposed by van de Kerkhof and colleagues. Courtesy of Amanda E Zubek, MD, PhD, FAAD.
Brittle nail syndrome: Moderate-to-significant longitudinal ridging of the R2-R5 fingernails in an otherwise healthy 77-year-old woman. Courtesy of Amanda E Zubek, MD, PhD, FAAD.
Brittle nail syndrome: A 75-year-old woman with a history of hypothyroidism with moderate-to-severe longitudinal ridging of the L2-L4 fingernails consistent with onychorrhexis. Courtesy of Amanda E Zubek, MD, PhD, FAAD.
Brittle nail syndrome: A 75-year-old woman with a history of hypothyroidism with moderate-to-severe longitudinal ridging of the R2-R4 fingernails, consistent with onychorrhexis. Courtesy of Amanda E Zubek, MD, PhD, FAAD.
Brittle nail syndrome: Horizontal splitting of the free margin of the nail consistent with lamellar onychoschizia. Courtesy of Springer Healthcare (Dermatology and Therapy, 20 Nov 2019).
Symptoms of Brittle Nail Syndrome
Patients with brittle nail syndrome may frequently report that their nails are fragile, break easily, and have difficulty preserving length. [6] These nail abnormalities most typically affect the first three fingernails, and fingernails are more frequently affected than toenails. [3, 7] Not only are these nail features frequently a cosmetic concern for patients, but they can also cause significant pain and discomfort. [8]
Pathophysiology
Brittle nails can be of primary origin or develop secondary to an underlying condition. [9] Primary brittle nails are speculated to develop from the impairment of intercellular adhesive factors of the nail matrix or abnormalities in epidermal growth and keratinization. Brittle nails of secondary origin are typically linked to disordered keratinization from dermatologic disease or systemic disorders, such as endocrine, metabolic, or vascular abnormalities. Other precipitating factors for brittle nails include the repetitive wetting and drying of the hands, direct contact with chemicals (nail polish remover), trauma to the nail, and onychomycosis. [1]
Etiology of Brittle Nail Syndrome
Lifestyle factors
An increased risk for these nail abnormalities has been attributed to patients who manicure frequently, have occupations that require frequent handwashing or manipulation of the hands, and those who smoke tobacco. [1, 3]
Dermatologic diseases
Brittle nail syndrome has been associated with pemphigus vulgaris, psoriasis, eczema, lichen planus, alopecia areata, lichen striatus, scleroderma, Darier disease, discoid lupus erythematosus, and pityriasis rubra pilaris, among other conditions. [8, 10, 11]
Genetic diseases
It has been associated with numerous genodermatoses, including punctate palmoplantar keratoderma, [12] as well as congenital hemidysplasia with ichthyosiform erythroderma (or nevus) and limb defects (CHILD) syndrome, among many others. [13]
Systemic diseases
Onychorrhexis has been described in a wide variety of systemic diseases. It has been associated with liver disease (most commonly hepatitis C virus infection and cirrhosis), [3, 14] thyroid disease, [15] hypoparathyroidism, [16, 17] and chronic renal failure. [18] It has also been associated with vascular diseases such as peripheral arterial disease, arteriosclerosis, microangiopathy, Raynaud disease, anemia, and polycythemia vera, as well as rheumatologic diseases such as gout, osteoarthritis, polyarteritis nodosa, rheumatoid arthritis, systemic lupus, and systemic sclerosis. [2, 14] Onychorrhexis can also be seen in graft versus host disease, sarcoidosis, primary systemic amyloidosis, and chronic immunosuppressed disorders such as severe combined immunodeficiency or AIDS. [14]
Mineral abnormalities
It has been associated with iron-deficiency anemia, arsenic poisoning, and zinc deficiency. [19]
Medication adverse effects
Brittle nails have been documented as an adverse effect of cancer therapy, including the Bruton tyrosine kinase inhibitor ibrutinib. [20] It has also been associated with azidothymidine, etanercept, hydroxyurea, itraconazole, and retinoid use. [14]
Epidemiology
Frequency
Brittle nail syndrome affects approximately 20% of the population. [1] Onychoschizia is estimated to affect up to 35% of adult women specifically. [19] The prevalence rate of onychorrhexis alone has not been well-described in literature.
Sex
It is reported to have a notable increased prevalence in women. [1]
Age
It has an increased prevalence in adults older than 60 years. [1] Commonly referred to as a senile disorder, onychorrhexis has been associated with the age-related reduction in cholesterol sulfate within the nail over time. [21] The older age predilection may also be linked to the increased likelihood of impaired circulation and concurrent dermatologic or systemic disease with age. [4]
Race
Racial predilection of secondary onychorrhexis, if at all, may relate to the racial prevalence of the underlying disease.
Prognosis
The condition is not considered life-threatening. However, it can have a negative impact on quality of life and may impede with one’s daily activities and occupational responsibilities. [2] Idiopathic onychorrhexis is typically milder than onychorrhexis associated with inflammatory nail matrix diseases, such as lichen planus. [4] It can take a significant amount of time for patients to notice major clinical improvement, especially given the slow growth of the nail plate (range, 0.5-1.2 mm/wk), [22] and that many systemic conditions known to contribute to onychorrhexis are considered chronic.
Patient Education
Patients can help reduce damage to their nails and cuticles by using nail moisturizers and protecting their hands during daily tasks. Examples of nail moisturizers include petroleum jelly, lactic acid lotion, mineral oil, and urea cream. Nail moisturizers can be combined with lukewarm water soaks lasting 10-20 minutes. This increases hydration in the nail plate and improves the appearance of nail fragility. Wearing gloves for household chores and keeping hands dry help protect nails and cuticles. Wearing gloves also helps protect nails from harsh chemicals such as cleaners, solvents, and detergents.
Patient education articles include Nail Injuries, Finger Infection, and Onychomycosis.
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Brittle nail syndrome: Significant longitudinal ridging of the L1 and R1 fingernails in an otherwise healthy 77-year-old woman, consistent with onychorrhexis stage 3 ridging per grading criteria proposed by van de Kerkhof and colleagues. Courtesy of Amanda E Zubek, MD, PhD, FAAD.
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Brittle nail syndrome: Horizontal splitting of the free margin of the nail consistent with lamellar onychoschizia. Courtesy of Springer Healthcare (Dermatology and Therapy, 20 Nov 2019).
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Brittle nail syndrome: Moderate-to-significant longitudinal ridging of the R2-R5 fingernails in an otherwise healthy 77-year-old woman. Courtesy of Amanda E Zubek, MD, PhD, FAAD.
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Brittle nail syndrome: A 75-year-old woman with a history of hypothyroidism with moderate-to-severe longitudinal ridging of the L2-L4 fingernails consistent with onychorrhexis. Courtesy of Amanda E Zubek, MD, PhD, FAAD.
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Brittle nail syndrome: A 75-year-old woman with a history of hypothyroidism with moderate-to-severe longitudinal ridging of the R2-R4 fingernails, consistent with onychorrhexis. Courtesy of Amanda E Zubek, MD, PhD, FAAD.
Tables
Lamellar splitting defined as onychoschizia |
0 = None, clear of clinical signs of lamellar nail splitting |
1 = Mild, distal furrows, parallel to the back surface, not involving the entire free edge of the nail plate |
2 = Moderate, distal parallel furrows of the superficial nail plate involving the complete free edge of the nail plate |
3 = Severe, distal lamellar splitting of the complete free edge of the nail plate, lamellar splits covering at least one third of the nail plate |
Horizontal nail splitting from the free edge of the nail plate |
0 = None, clear of clinical signs from the free edge of the nail plate |
1 = Mild, one superficial horizontal split of the distal nail plate |
2 = Moderate, 2-3 horizontal splits of the distal nail plate |
3 = Severe, multiple horizontal splits leading to loosening of at least one third of the distal nail plate |
Assessment of ridges and longitudinal grooves |
0 = None, clear of any signs of ridging and longitudinal grooves |
1 = Mild, few plane ridges and longitudinal grooves |
2 = Moderate, few deep ridges and longitudinal grooves |
3 = Severe, more than 70% of the nail plate showing deep ridges and corresponding grooves |
Longitudinal splitting as derived from the nail matrix and defined as onychorrhexis |
0 = None, clear of clinical signs of longitudinal nail splitting |
1 = Mild, one single, superficial longitudinal split of the nail plate |
2 = Moderate, at least one deep longitudinal split of the entire nail plate |
3 = Severe, multiple, superficial and deep longitudinal splits of the nail plate |
