Abstract
The growing demand for natural treatments has raised concerns among clinicians due to limited scientific evidence supporting their use. This review article addresses the issue by assisting dermatologists and general practitioners in recommending natural treatments for the following common nail disorders: nail brittleness, onychomycosis, periungual verrucae, paronychia, chloronychia, nail psoriasis, nail lichen planus, onychocryptosis, onycholysis, and congenital malalignment of the great toenail. One limitation is the scarcity of existing reviews on natural treatment options for nail disorders in the literature. Through a comprehensive review of existing literature, this article consolidates the available evidence on natural treatment options for these conditions. Although some natural treatments for nail disorders are supported by scientific evidence, the indiscriminate use of such remedies may lead to severe poisoning and health problems. Given the widespread and increasing use of natural treatments, clinicians play a pivotal role in educating patients about evidence-based remedies and debunking misleading claims. By doing so, clinicians can enhance patient safety and improve treatment outcomes. It is essential for healthcare professionals to be well-informed and equipped with the knowledge to differentiate between effective natural treatments and unverified claims, ensuring that patients receive appropriate care.
Introduction
Patients in the US are expressing an increased interest in natural treatments, with as many as 85% already using them [1]. Despite the growing demand, many clinicians feel uncomfortable recommending such remedies due to limited scientific evidence [1]. To our knowledge, no reviews on natural treatment options for nail disorders exist in the literature. This article thus assists dermatologists and general practitioners in recommending natural treatments and measures for the following common nail disorders: nail brittleness, onychomycosis, periungual verrucae, paronychia, chloronychia, nail psoriasis, nail lichen planus, onychocryptosis, onycholysis, and congenital malalignment of the great toenail.
Nail Brittleness
Brittle nail syndrome is characterized by the presence of both lamellar onychoschizia, defined as fine horizontal splits within the nail plate due to the loss of intracellular adhesion, and onychorrhexis, defined as longitudinal shallow splitting or ridging of the superficial nail plate (shown in Fig. 1, 2). The condition affects up to 20% of the population, especially women older than 50 years of age, and is most commonly seen on the fingernails [2]. It is generally secondary to external insults, such as exposure to excessive wet-dry environments and the application of formaldehyde-based nail hardeners. Although generally benign, nail brittleness affecting both fingernails and toenails may be a manifestation of an underlying systemic disease process [3].
Brittle nail: clinical image showing clear, fine horizontal splits within the nail plate (onychoschizia) and some longitudinal shallow ridging (onychorrhexis).
Brittle nail: clinical image showing clear, fine horizontal splits within the nail plate (onychoschizia) and some longitudinal shallow ridging (onychorrhexis).
Dermoscopic image of a brittle nail, showing severe longitudinal shallow ridging and splitting of the superficial nail plate (onychorrhexis).
Dermoscopic image of a brittle nail, showing severe longitudinal shallow ridging and splitting of the superficial nail plate (onychorrhexis).
Treatment
Clinical improvement, namely fingernail firmness and hardness, has been reported with at least 6 months of daily oral 5–10 mg biotin (vitamin B7) supplementation [4]. These clinical observations were further confirmed by confocal electron microscopy; daily supplementation with 2.5 mg of oral biotin led to a 25% increase in nail thickness in treated patients compared to untreated controls [4]. Moreover, a recent clinical trial exploring the efficacy of daily hydroxypropyl chitosan-based lacquer, alone or combined with 10 mg of oral biotin, revealed a significant improvement in nail dystrophy, lamellar and longitudinal splitting, dyschromia, and pitting as per the Onychodystrophy Global Severity Score (OGSS) with the combination treatment [5]. Although supplementation with this water-soluble vitamin is highly unlikely to be associated with significant adverse effects, it is important to note that high-dose biotin supplementation can falsely alter the results of certain laboratory tests, namely troponin, thyroid hormone, or prolactin levels as well as at-home urine and pregnancy tests, especially when performed with traditional laboratory assays [2, 6]. Newer assays have shown less interference with biotin [7, 8].
When ferritin levels are under 10 ng/mL, a combination of iron supplementation and vitamin C may be useful [2]. In patients with primary and secondary zinc deficiencies, supplementation of 20–30 mg of zinc per day appears to improve nail strength [2]. One study reported that a biomineral oral supplement containing amino acids (l-cystine, l-arginine, and glutamic acid), vitamins (C, E, B6, and B7), and minerals (zinc, iron, and copper) improved the fingernail strength of patients with brittle nails after 3 months of use [9].
Nail moisturizers that contain occlusives, like petrolatum or lanolin, and humectants, like glycerin and propylene glycol, improve nail strength [3]. Proteins, fluorides, and silicon can be useful as well [3]. What’s more, the addition of alpha-hydroxy acids and urea increases the water-binding capacity of the nail plate [3]. Jojoba oil may also be effective, as it can form a protective film on the nail surface, protecting it from further environmental damage [10].
Recommended Measures
Reduce contact with water and detergents.
Wear cotton gloves inside rubber gloves.
File nails in one direction.
Keep nails short and squared.
Limit the use of nail polish removers, especially alcohol-based ones, to twice a month at most.
Favor the use of acetate-based over acetone-based nail polish removers.
Apply topical moisturizers to the nails after soaking.
Leave cuticles uncut.
Avoid manicuring with sharp tools.
Avoid long-term wearing of artificial nails.
Avoid work-related microtraumas.
Discontinue the use of any formaldehyde-containing product [3].
Onychomycosis
Onychomycosis is a fungal infection of the nail unit and is the most prevalent of all nail ailments [11]. It can be found in up to 13% of the general population, with a prevalence reaching 48% in those 70 years of age or older [11]. Involvement of the toenails is most common and typically precedes fingernail involvement.
Treatment
Tea tree oil may, with long-term use, be an effective treatment approach. In a double-blind, multicenter, randomized control trial involving 177 individuals with toenail onychomycosis, twice-daily application of 100% tea tree oil in conjunction with serial debridement was as effective as that of 1% clotrimazole solution with serial debridement, based on fungal culture results and clinical assessment after 6 months of treatment [12]. Around two-thirds of the patients in each study arm reported sustained or continued improvement of their symptoms 3 months after study completion. However, in a double-blind, randomized, placebo-controlled study involving 60 individuals with toenail onychomycosis, 80% of patients using the 2% butenafine hydrochloride and 5% melaleuca alternifolia (tea tree) oil cream were mycologically cured, as opposed to 0% of those using only the 5% tea tree oil cream [13]. It is important to note that confirming a diagnosis of onychomycosis is recommended prior to using over-the-counter antifungal treatment such as butenafine, in the wake of cross-reactivity and increasing resistance to prescription equivalents such as terbinafine [14].
An alternative treatment approach involves the use of over-the-counter mentholated ointments, such as Vicks VapoRub (The Proctor & Gamble Company, Cincinnati, OH, USA). The main ingredients of Vicks VapoRub include camphor 4.8%, eucalyptus oil, menthol 2.6%, thymol, amongst others. Thymol, or 5-methyl-2-(1-methylethyl) phenol, is a phenol derivative with antiseptic and preservative properties. In a clinical case series, 83% of participants had a positive treatment effect at week 48 of treatment with Vicks VapoRub, 27.8% exhibiting both a mycological and clinical cure [15].
Recommended Measures
Clean and dry hands and feet [16, 17].
Keep fingernails and toenails clean and short [17].
Disinfect old footwear and socks [17].
Ensure that nail manicure tools have been appropriately sterilized before use in commercial salons to prevent cross-infection.
Wear loose, closed toe shoes [16].
Avoid walking barefoot in public areas [16].
Periungual Verrucae
Periungual verrucae (warts) are present around the nails, initially appearing shiny and smooth but gradually becoming dirty and rough (shown in Fig. 3, 4) [18]. They may be difficult to treat and can easily spread to other parts of the body through direct contact with individuals who have the human papillomavirus or through indirect contact with contaminated objects [19].
Periungal verrucae of the lateral aspect of nail fold groove of the third and fourth digits, clinically presenting as a rough, dirty brown papule.
Periungal verrucae of the lateral aspect of nail fold groove of the third and fourth digits, clinically presenting as a rough, dirty brown papule.
Treatment
Intralesional vitamin D3 injections may be effective, as a study involving 14 patients who had periungual verrucae and were injected with 0.2–0.5 mL of vitamin D3 every 2 weeks for a maximum of 4 sessions showed complete clearance in 13 patients and moderate clearance in 1 [20]. It is important to mention to patients that this procedure is painful and that alternatives are available.
Local hyperthermia treatment is an emerging therapeutic modality. Two patients with periungual verrucae received local hyperthermia irradiation at 44°C for 30 min at a time, 5 times over 2 weeks, and then once weekly for 6 more weeks. Complete resolution of their lesions was reported, and no relapse occurred during the short-term follow-up, 2 months after the last treatment [21].
Salicylic acid and lactic acid formulations are alternative treatment options [22]. Tea tree oil has shown efficacy in cutaneous warts refractory to treatment with 12% salicylic acid and 4% lactic acid. In a reported case of recurrent cutaneous warts affecting the right middle finger of a 7-year-old pediatric patient, once daily application of 100% tea tree oil for 12 days resulted in symptom resolution; no recurrence was noted [23].
Recommended Measures
Observe good hygiene in public areas.
Wash hands regularly.
Avoid sharing nail trimmers and manicure equipment.
Avoid fingernail biting [18].
Paronychia
Paronychia is an inflammation of one or more of the three nail folds surrounding fingernails or toenails [24]. It can be acute (less than 6 weeks) or chronic (6 weeks or more). Acute paronychia is usually secondary to polymicrobial infections, whereas chronic paronychia results from irritant dermatitis [24].
Treatment
Treatment of acute paronychia depends on the severity of inflammation and the presence of an abscess, which mandates drainage [24]. In cases of mild inflammation uncomplicated by an abscess, the use of warm soaks is recommended as they promote spontaneous drainage [24]. Moreover, warm soaks combined with Burow’s solution (aluminum acetate solution) and vinegar (acetic acid) are a time-tested topical treatment [24]. Patients with recurrent acute paronychia are commonly methicillin-resistant Staphylococcus aureus (MRSA) carriers. Emerging data highlight the efficacy of Saudi Sumra honey against pathogenic bacteria, including MRSA. However, this remains largely in vitro, and further investigation pertaining to the potential clinical implications is needed [25].
Recommended Measures
Keep nails short.
Keep affected area dry.
Wear cotton gloves inside rubber gloves.
Apply moisturizer after washing hands.
Choose proper footwear to avoid unnecessary nail damage.
Avoid exposure to moist environments and contact irritants.
Avoid manipulation of the nails [26].
Chloronychia
Chloronychia, or green nails (shown in Fig. 5), is an infection that is usually caused by Pseudomonas aeruginosa but can be caused by other bacterial or fungal contamination [28]. Additional features on physical examination include distolateral onycholysis and paronychia. Most affected patients have a history of nail disorders or trauma, leading to onycholysis and subsequent nail bed infection.
Clinical image of chlonychia, or green nails, with features of distolateral onycholysis.
Clinical image of chlonychia, or green nails, with features of distolateral onycholysis.
Treatment
Treatment may involve keeping nails dry to prevent the persistence of the contaminant and applying 1% acetic acid compresses [29]. The use of chlorine bleach diluted to 1:4 with water has also been reported in the literature [29]. It is recommended that soaks be performed twice a day for 3–4 weeks [30].
Recommended Measures
Nail Psoriasis
Nail involvement in psoriasis has a lifetime incidence of 80–90% and varying prevalence of 10–82% [32]. Clinically, psoriatic nails will show characteristic superficial depressions, or pitting, and may also demonstrate onycholysis, subungual hyperkeratosis, and splinter hemorrhages (shown in Fig. 6).
Nail psoriasis is the sole presenting feature of psoriasis in 5–10% of patients with no plaque disease and has been identified as an independent prognostic factor for the development of psoriatic arthritis (PsA). It is also associated with impairment of patients’ quality of life [32].
Treatment
Vitamin D derivatives, including calcipotriol, tacalcitol, and calcitriol, are commonly used in the treatment of nail psoriasis [33]. Combined with other treatments, vitamin D derivatives constitute the ideal treatment because their application may be maintained for long periods of time [33]. Their use has been strongly recommended by experts for few-nail disease and isolated nail matrix involvement [32].
Furthermore, many studies have shown that daily supplementation of omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) improves psoriasis symptoms [33]. In a study involving 30 patients with mild or moderate plaque psoriasis, 15 patients were given topical tacalcitol, whereas the remaining 15 were given both topical tacalcitol and 2 capsules of omega-3 fatty acids [33]. A significant improvement in the Nail Psoriasis Severity Index (NAPSI) was observed in both groups, but the improvement was significantly greater in the group treated with omega-3 fatty acids [33]. Wheat germ oil, flaxseed oil, black seed oil, and violet oil are recommended by Iranian traditional medicine [34].
Recommended Measures
Keep nails short [35].
Wear gloves when performing manual labor [35].
Moisturize hands [35].
Leave cuticles uncut [35].
Avoid wearing artificial nails [35].
Avoid sun exposure as it may worsen nail psoriasis [36].
Minimize nail trauma by avoiding regular manicures and pedicures, especially if involving abrasive methods of nail decoration (e.g., gel polish removal with nail plate filing).
Nail Lichen Planus
Nail lichen planus (NLP) is a chronic inflammatory disorder that may cause permanent nail scarring if left untreated [37]; therefore, prompt treatment is necessary [38]. Involvement and thinning of the entire nail matrix common, leading to nail atrophy with loss of normal anatomy, potentially through dorsal pterygium formation (fusion of the proximal nail fold with the underlying matrix) with or without trachonychia (rough “sandpaper-like” nail plate) (shown in Fig. 7).
Nail lichen planus affecting all digits of the hands, showing characteristic nail plate anatomical distortion and atrophy, with distal splitting of the thumbs fingernails bilaterally.
Nail lichen planus affecting all digits of the hands, showing characteristic nail plate anatomical distortion and atrophy, with distal splitting of the thumbs fingernails bilaterally.
Treatment
A nail lacquer containing urea, keratinase, and a retinoid molecule shows promise as a treatment for NLP, as a 12-week study involving 10 patients with NLP showed an 81% reduction in the severity of NLP with a once daily application of the lacquer [38].
Recommended Measures
Early diagnosis.
Early initiation of treatment to prevent permanent nail damage.
Keep nails short.
Wear gloves when performing manual labor.
Avoid biting and picking.
Minimize nail trauma by avoiding regular manicures and pedicures, especially if involving abrasive methods of nail decoration (e.g., gel polish removal with nail plate filing).
Onychocryptosis
Onychocryptosis, or an ingrown toenail, results from the penetration of the nail plate into the skin. It mostly affects the great toenail and is classified into mild, moderate, and severe [39]. It is often painful for patients and may be accompanied by purulent discharge or surrounding erosions.
Treatment
Treatment approaches for patients with mild or moderate onychocryptosis include soaking the foot in warm, soapy water for 10–20 min or placing cotton under the ingrown lateral nail edge using a nail elevator or small curette [39]. Inserting dental floss obliquely under the ingrown nail corner to separate it from the nail fold and gutter splinting of the lateral edge of the nail with sized sterile vinyl intravenous infusion tubes are options that provide instant relief of pain [39‒41].
Alternatively, taping procedures may be used to pull the side of the nail fold away from the nail to decrease pressure in a safe and painless fashion [42].
Recommended Measures
Onycholysis
Onycholysis is the separation of the nail plate from the underlying bed [27]. Both fingernail and toenail onycholysis are usually caused by trauma [43]. It can also be secondary to distorted nail unit anatomy as with congenital malalignment of the great toenails. More rarely, it is associated with systemic diseases, such as thyroid dysregulation or blistering diseases, as well as the use of medications, most commonly tetracyclines, quinolones, oral contraceptives, and chemotherapeutic agents. Although onycholysis itself is benign, it puts patients at risk of developing bacterial or fungal infections of the nail unit.
Treatment
Idiopathic fingernail onycholysis can be treated by removing traumatic stimuli, like bandages, gloves, and topical formulations, that can promote the thriving of microbial flora by retaining moisture in the onycholytic space [43]. Dry air from a hair dryer on the “lytic” area once or twice per day can also control the colonizing biota [43]. Toenail onycholysis due to asymmetric gait nail unit signs can be treated with custom-made insoles to even plantar surfaces and correct the gait [43].
Recommended Measures
Congenital Malalignment of the Great Toenail
Congenital malalignment of the great toenails is a dystrophic disorder characterized by lateral deviation of the nail unit, resulting in altered growth of the nail plate, that typically presents in infancy or early childhood [45] (shown in Fig. 8). Characteristic features include onychauxis (nail plate thickening), variable chromonychia (nail plate discoloration), and transverse ridging [45]. It is commonly associated with the development of ingrown toenails (onychocryptosis), distal nail plate separation (onycholysis), and nail fold inflammation (paronychia).
Treatment
Spontaneous realignment is only seen in up to 50% of patients before 10 years of age [46]. As such, conservative treatment, like wearing comfortable, proper-fitting shoes to minimize trauma, may be favored until then depending on the degree of symptom severity [47]. This, however, is highly controversial, and expert recommendations favor surgical treatment of the deformity within 2 years of age [48].
Recommended Measures
Wear comfortable footwear and avoid trauma to the nail unit.
Observe foot hygiene.
Consider pursuing surgical treatment.
Conclusion
Some natural treatments for nail disorders are supported by science. However, the common misconception that all natural products are nontoxic and devoid of adverse effects can lead to severe poisoning and health problems [49]. Because of the widespread and increasing use of natural treatments, clinicians should be well-equipped to educate patients on which remedies are evidence based and which are tall tales in order to improve patient safety and treatment outcomes.
Statement of Ethics
Written informed consent was obtained from patients for publication of their clinical images.
Conflict of Interest Statement
The authors have no conflicts of interest to declare.
Funding Sources
There were no sources of financial assistance to conduct the study/analysis described in the manuscript and/or used to assist with the preparation of the manuscript.
Author Contributions
D.B. and M.Y. participated in conceptualization, literature review, manuscript drafting, and editing. J.K. and B.M. provided oversight and participated in manuscript drafting and editing. All authors read and approved the final version of this manuscript.