Yellow Nail Syndrome


Continuing Education Activity

Yellow nail syndrome (YNS) is a rare condition defined by a presence of two of the following: (1) slow-growing, hard, yellow, and dystrophic nails, (2) lymphedema, and (3) respiratory tract disease. The earliest case of YNS was reported by Heller in 1927. However, in 1947, Samman and White published the first case series of YNS in patients with nail discoloration and lymphedema. Pulmonary disease, specifically pleural effusion, was added to the diagnostic criteria by Emerson in 1966. In general, the syndrome is acquired and affects adults over age 50. However, there are case reports of YNS occurring in children and even newborns. This activity describes the evaluation and management of yellow nail syndrome and reviews the role of the interprofessional team in evaluating and improving care for patients with this condition.

Objectives:

  • Describe the common presentation of a patient with yellow nail syndrome.
  • Explain the common physical exam findings associated with yellow nail syndrome.
  • Review the reasons for a delayed diagnosis of yellow nail syndrome.
  • Outline interprofessional team strategies for improving care coordination and communication to advance yellow nail syndrome and improve outcomes.

Introduction

Yellow nail syndrome (YNS) is a rare condition defined by a presence of two of the following: (1) slow-growing, hard, yellow, and dystrophic nails, (2) lymphedema, and (3) respiratory tract disease.[1] The earliest case of YNS was reported by Heller in 1927.[2] However, in 1947, Samman & White published the first case series of YNS in patients with nail discoloration and lymphedema.[3] Pulmonary disease, specifically pleural effusion, was added to the diagnostic criteria by Emerson in 1966.[4] In general, the syndrome is acquired and affects adults over age 50. However, there are case reports of YNS occurring in children and even newborns.[5]

Anatomically, YNS affects the fingernails, toenails, the respiratory tract, and gravity-dependent areas that can accumulate fluid (typically lower extremities). These signs and symptoms are believed to be due to dysfunction in lymphatic drainage.[3][4][6][7]

Nails

As the name suggests, xanthonychia (yellow nail coloration) is a common feature of YNS; however, yellow nails are not required if two of the other clinical signs are present. Discoloration varies from pale yellow to dark green; nails can be opaque or translucent.[8] The manifestations are commonly misdiagnosed as onychomycosis (discoloration due to fungal infection), as the nails may become thickened, hard, and curved.[9] A quick inspection of fingernails and toenails can help expand the differential for a patient with other vague complaints without adding additional expense.

Respiratory Tract

The respiratory tract is involved in more than half of patients with YNS.[2][7] The most common manifestation is a chronic cough, followed by pleural effusion.[7] In one of the largest reviews of patients with YNS, Valdés et al. found nearly all effusions to be exudative with a lymphocytic predominance. Of the 66 subjects, approximately 70% of effusions were bilateral.[2][10] Other pulmonary manifestations include bronchiectasis, recurrent pneumonia, sinusitis, and pulmonary fibrosis.[11] Pulmonary function testing in YNS is typically unremarkable, and biopsies do not usually contribute to the diagnosis.[10]

Lymphedema

Lymphedema typically manifests in the bilateral lower extremities and does not differ in appearance from primary lymphedema.[2] Lymphedema occurs in 30% to 80%.[2][7][12] Dynamic lymphatic imaging (lymphoscintigraphy) does differ between patients with edema related to YNS and those with primary lymphedema.[13] Edema can be pitting and can be easily confused with fluid accumulation often seen in patients with decompensated congestive heart failure. This can be especially deceiving if patients present with concurrent pleural effusions. As in primary lymphedema, treatments often involve massage, compression dressing, exercises, and less commonly, surgical interventions.[14]

Natural History 

The diagnosis of YNS can be difficult because patients rarely present concurrently with all three clinical criteria. Lymphedema is the initial symptom in approximately one-third of YNS diagnoses.[12] Prognosis and disease course depend on the individual's symptoms and timing of diagnosis. In some mild cases, the symptoms of YNS can resolve without intervention. Unfortunately, many symptoms recur despite treatment and require continuous care. YNS has the potential to affect one's quality of life, including both cosmesis and worsening functional status. Recurring soft tissue infections (e.g., cellulitis from severe lymphedema), pulmonary infections (pneumonia/empyema), and pulmonary effusions can lead to complications such as antibiotic resistance, pulmonary scarring, and protein loss.[15] 

Etiology

The specific cause of yellow nail syndrome (YNS) is unclear. The most widely accepted explanation for the signs and symptoms associated with YNS is a dysfunction of the lymphatic system, specifically, lymphatic drainage.[2][4][16] Imaging of the lymphatic system and lymph transport using lymphoscintigraphy is abnormal in YNS.[2] Interestingly, studies have shown that there is a difference in lymphatic drainage in patients with YNS compared to those with primary lymphedema. [2][13] Another proposed etiology of YNS is exposure to titanium, specifically titanium dioxide (used in various products such as dental and joint implants, surgical staples, and various cosmetics).[17][18] When compared to healthy controls, nail clippings from patients with YNS contained elevated levels of titanium.[17][19] Furthermore, case reports exist in which the removal of titanium-containing implants led to the resolution of YNS.[19] Rare cases have also been reported after mitral valve replacement.[20]

While cases of familial and congenital YNS have been reported, in the majority of cases, YNS is an acquired disorder of the lymphatic system that presents later in life.[21] YNS has also been associated with certain malignancies, autoimmune diseases, and immunodeficiency disorders.[22][23][24] 

Epidemiology

The exact prevalence of YNS is unknown, and the majority of the literature pertaining to YNS involves case reports. The estimated prevalence is less than 1/1,000,000.[2] It occurs more commonly after the age of 50, affecting males and females equally.[7][12] Congenital and pediatric cases are extremely rare.[5][25][26] If YNS is suspected in a young patient, special care should be taken to rule out other related disorders of the lymphatic system.

Pathophysiology

As the underlying cause of YNS is unknown, the pathophysiology is also unclear. The most widely accepted cause of YNS is thought to be related to abnormalities in lymphatic flow. Based on their investigations involving quantitative lymphoscintigraphy, Bull et al. argue that unlike primary lymphedema, which is due to permanent structural lymphatic abnormalities, the abnormalities observed in YNS appears to be functional and potentially reversible.[13] They propose that perhaps an inflammatory component that leads to altered capillary permeability, fluid shifts, and alterations in blood flow is likely the cause of the edema in YNS.

Histopathology

Histopathological examination of nails is important to rule out other more common causes of yellow nails, such as onychomycosis. The appearance of nails in YNS is varied. Changes include a thickened nail plate with exaggerated curvature, xanthonychia (yellow discoloration), scleronychia (hardening of the nail), onycholysis (separation of the nail plate and nail bed), and slow growth.[2][9]

When a pleural effusion is present, thoracentesis and examination of the fluid typically reveal a serous exudative effusion.[10] In their case series study, Valdés et al found that pleural fluid samples most often had lymphocytic predominance with low numbers of nucleated cells with a pleural fluid protein of greater than 3 g/dL.

History and Physical

History

A thorough history is crucial to diagnosing YNS. Open-ended questioning and a detailed review of the pulmonary, vascular, and integumentary systems can reveal clues that may lead to the diagnosis of this rare syndrome. The pulmonary findings in YNS vary widely. It is important to ask about persistent cough, congestion, and recurrent respiratory infections. Review of past medical history, social history (i.e., smoking status, exposures to respiratory irritants), and previous chest imaging are essential. Remember that symptoms can be mild, intermittent, and may not present concurrently. 

Physical Exam

Special attention should be paid to analyzing fingernails and toenails and removing polish if necessary. Nail findings can be subtle, the discoloration can range in intensity from pale yellow to green.[8] Nails can be thickened or irregular, and are often slow-growing and brittle.[9] 

The physical appearance of lymphedema in YNS is no different than what is seen in primary lymphedema. Based on case reports, lymphedema is the initial symptom of YNS in approximately one-third of patients, and it is present in approximately 30% to 80% of those diagnosed with the syndrome.[2][7][12] Lymphedema is most commonly found in the bilateral lower extremities and other gravity-dependent areas.[2] Although clinical signs have poor diagnostic reliability, the Kaposi-Stemmer sign (inability to pinch and lift the skin at the dorsum of the base of the second toe) has been shown to be the most useful.[27] Early in the course of lymphedema, pitting is present, however as it progressed and the skin thickens and hardens pitting is less clear.[28] Edema associated with venous obstruction and lymphedema is often difficult to distinguish. 

Respiratory tract manifestations in YNS occur in 60% to 70% of patients, the most common of which is a chronic cough.[2][7] A careful history will help to direct a thorough physical exam. Pleural effusions can be detected through auscultation and percussion. Facial fullness, tenderness to palpation of sinuses, and edematous nasal turbinates can be a sign of chronic sinusitis.[29] Other pulmonary manifestations, such as bronchiectasis and fibrosis.

Evaluation

The diagnosis of YNS is clinical, and no specific test is required or diagnostic. More commonly encountered diagnoses, such as heart failure, primary lymphedema, and onychomycosis, should be ruled out. This can be done through a thorough investigation of the patient's history and physical exam or may require additional tests. Potential testing may include the following:

  • Echocardiography to rule out heart failure
  • Chest radiography to identify pneumonia or other pulmonary pathology
  • CT of the sinuses to assess for chronic sinusitis
  • Testing for infection, such as sputum analysis or CBC
  • Analysis of nail scrapings or clippings to rule out onychomycosis
  • Thoracentesis with an evaluation of pleural fluid
  • Lymphoscintigraphy to identify lymphatic insufficiency

Treatment / Management

The management of yellow nail syndrome (YNS) focuses on treating symptoms. If thought to be a paraneoplastic syndrome, the treatment of underlying cancer may lead to resolution.[30] Sometimes, YNS can resolve without intervention.[2]

Pulmonary Symptoms

Pleural effusions are usually treated with thoracentesis. Octreotide has been shown to be effective in some cases of chylous effusions associated with YNS.[31] Unfortunately, pleural effusions tend to recur and may require definitive interventions, including decortication, pleurodesis, or thoracic duct embolization.[10] Antibiotic prophylaxis can be offered if the patient has recurrent infections or advanced bronchiectasis.[11] Pneumococcal and seasonal influenza vaccines are recommended.[2] 

Dystrophic and Discolored Nails

Nail disease in YNS can resolve spontaneously. Evidence for using oral vitamin E to treat nail discoloration has mixed success.[32] Antifungals, either alone or in combination with vitamin E, have been used despite the absence of fungal infection.[33] Other treatments have been proposed, such as oral zinc, clarithromycin, and corticosteroid injections have poor evidence to support their use.[34][35][36]

Lymphedema

Lymphedema observed in YNS is treated with the same interventions used in primary lymphedema. Generally, non-surgical interventions are used, including compression garments and bandaging used in combination with skincare, manual lymph drainage, and exercises.[37]

Differential Diagnosis

Because YNS involves multiple symptoms from various organ systems, the differential diagnosis is broad. 

The pulmonary manifestations of YNS, such as pleural plaques and pleural thickening, have similar characteristics to asbestos-related lung disease.[38] Heart failure, which is far more prevalent than YNS, is commonly associated with lower extremity edema and pulmonary effusions in its decompensated state.[39] Edema due to vascular congestion is usually improved with diuresis, which is not the case with lymphedema. Systemic illnesses, such as connective tissue disease, autoimmune conditions, various malignancies, endocrine abnormalities, and immunodeficiency states, can be associated with yellow nails.[2] Onychomycosis must also be considered in patients with yellowed dystrophic nails.[40]

Prognosis

Prognosis in YNS is dependent on the specific symptoms of the patient and co-existing illnesses. Symptoms range from mild (poor nail cosmesis and chronic cough) to severe (marked and recurring edema, persistent pulmonary infections). There is no cure for YNS. Treatment is aimed at improving symptoms.

Complications

Because YNS involves multiple organ systems, complications depend on which specific symptoms the patient exhibits. Dystrophic and discolored nails can cause psychological distress from embarrassment, and onycholysis can be painful.[2] There are potentially life-threatening complications related to the pulmonary and lymphatic manifestations observed in YNS.

Pulmonary

Large and persistent pleural effusions are uncomfortable and can cause a significant decline in functional status. Effusions are associated with other potentially fatal complications, such as infection and respiratory distress.[10] Often, serial thoracenteses are required and carry the risk of infection, bleeding, pneumothorax, and significant discomfort.[41] Frequent draining of pleural effusions (which are high in protein) can lead to hypoalbuminemia, which further exacerbates edema and the recurrence of effusions.[42] Frequent prescribing of antimicrobials due to recurring respiratory infections can lead to antibiotic resistance.

Lymphatic

Significant edema usually affects the bilateral lower extremities leading to difficulty with ambulation and deconditioning. Furthermore, longstanding lymphedema leads to changes in skin texture and color, which can be esthetically unappealing and can lead to cellulitis and other infections.[43][44] Additional areas for fluid accumulation include the peritoneal space, which may require paracentesis, genitalia, leading to tissue breakdown and discomfort, and the periorbital area, which can cause difficulty with vision.[45]

Deterrence and Patient Education

Yellow nail syndrome is an extremely rare diagnosis. It can go undiagnosed for misdiagnosed for years before other more common conditions are ruled out. The interprofessional team and caretakers must advocate for further investigation and consideration of differential diagnoses if standard therapy is not successful. There is no specific treatment for YNS; therefore, patients must be aware of the potential harms and limited success of any intervention.

Pearls and Other Issues

  • The diagnosis of YNS requires two of the following: yellow nails, lymphedema, and pulmonary disease.
  • YNS is often misdiagnosed as onychomycosis; however, histopathological analysis of nail samples is negative for fungus. Similarly, examination under Wood's lamp is typically negative.
  • YNS can mimic heart failure, a far more common condition, as it also can present with dyspnea on exertion, pleural effusion, and lower extremity edema.
  • Treatment for YNS is generally supportive and focused on treating symptoms. Oftentimes, symptoms improve regardless of intervention but usually recur.
  • Lymphoscintigraphy is a method used to assess lymphatic function. Testing is typically abnormal in patients with YNS but is less severe than those with primary lymphedema.
  • The exact mechanism of YNS is unknown, but it is thought to be due to functional impairment in the lymphatic system that leads to changes in capillary permeability.

Enhancing Healthcare Team Outcomes

Yellow nail syndrome (YNS) frequently goes undiagnosed or misdiagnosed for many years. These patients may exhibit non-specific signs and symptoms including cough, recurrent infection, lower extremity edema, and nail discoloration, which are present in conditions far more prevalent than YNS, such as heart failure, venous insufficiency, infection, or medication side-effect. It can lead to patients being referred to a myriad of specialists in the fields of cardiology, infectious disease, endocrinology, and pulmonology. Although a more common illness is more likely in patients who present with 2 or 3 signs and symptoms of the triad of YNS, health professionals must communicate effectively and rule out these other illnesses in a way that limits unnecessary testing, treatment, and consultation. Health care providers need to keep YNS on the differential as it is a clinical diagnosis.

Approximately one-third of patients with YNS have all three signs/symptoms simultaneously.[6] Furthermore, a single symptom may be present for several months or even years, which can make diagnosis difficult and delayed.[46] Detailed documentation of signs/symptoms and resistance to anchoring bias is essential to prompt diagnosis of YNS.



(Click Image to Enlarge)
Yellow nail syndrome
Yellow nail syndrome
Image courtesy S Bhimji MD
Article Details

Article Author

Megan Cheslock

Article Editor:

Douglas Harrington

Updated:

2/18/2021 9:28:51 AM

PubMed Link:

Yellow Nail Syndrome

References

[1]

Pavlidakey GP,Hashimoto K,Blum D, Yellow nail syndrome. Journal of the American Academy of Dermatology. 1984 Sep;     [PubMed PMID: 6384296]

[2]

Vignes S,Baran R, Yellow nail syndrome: a review. Orphanet journal of rare diseases. 2017 Feb 27;     [PubMed PMID: 28241848]

[3]

SAMMAN PD,WHITE WF, THE     [PubMed PMID: 14140738]

[4]

Emerson PA, Yellow nails, lymphoedema, and pleural effusions. Thorax. 1966 May;     [PubMed PMID: 5914998]

[5]

Nordkild P,Kromann-Andersen H,Struve-Christensen E, Yellow nail syndrome--the triad of yellow nails, lymphedema and pleural effusions. A review of the literature and a case report. Acta medica Scandinavica. 1986;     [PubMed PMID: 3962735]

[6]

Preston A,Altman K,Walker G, Yellow nail syndrome. Proceedings (Baylor University. Medical Center). 2018 Oct;     [PubMed PMID: 30949001]

[7]

Maldonado F,Tazelaar HD,Wang CW,Ryu JH, Yellow nail syndrome: analysis of 41 consecutive patients. Chest. 2008 Aug;     [PubMed PMID: 18403655]

[8]

Baran R, Pigmentations of the nails (chromonychia). The Journal of dermatologic surgery and oncology. 1978 Mar;     [PubMed PMID: 632390]

[9]

Stosiek N,Peters KP,Hiller D,Riedl B,Hornstein OP, Yellow nail syndrome in a patient with mycosis fungoides. Journal of the American Academy of Dermatology. 1993 May;     [PubMed PMID: 8496432]

[10]

Valdés L,Huggins JT,Gude F,Ferreiro L,Alvarez-Dobaño JM,Golpe A,Toubes ME,González-Barcala FJ,José ES,Sahn SA, Characteristics of patients with yellow nail syndrome and pleural effusion. Respirology (Carlton, Vic.). 2014 Oct;     [PubMed PMID: 25123563]

[11]

Woodfield G,Nisbet M,Jacob J,Mok W,Loebinger MR,Hansell DM,Wells AU,Wilson R, Bronchiectasis in yellow nail syndrome. Respirology (Carlton, Vic.). 2017 Jan;     [PubMed PMID: 27551950]

[12]

Piraccini BM,Urciuoli B,Starace M,Tosti A,Balestri R, Yellow nail syndrome: clinical experience in a series of 21 patients. Journal der Deutschen Dermatologischen Gesellschaft = Journal of the German Society of Dermatology : JDDG. 2014 Feb;     [PubMed PMID: 24134631]

[13]

Bull RH,Fenton DA,Mortimer PS, Lymphatic function in the yellow nail syndrome. The British journal of dermatology. 1996 Feb;     [PubMed PMID: 8746347]

[14]

Kayıran O,De La Cruz C,Tane K,Soran A, Lymphedema: From diagnosis to treatment. Turkish journal of surgery. 2017;     [PubMed PMID: 28740950]

[15]

Yu H, Management of pleural effusion, empyema, and lung abscess. Seminars in interventional radiology. 2011 Mar;     [PubMed PMID: 22379278]

[16]

Maldonado F,Ryu JH, Yellow nail syndrome. Current opinion in pulmonary medicine. 2009 Jul;     [PubMed PMID: 19373089]

[17]

Decker A,Daly D,Scher RK, Role of Titanium in the Development of Yellow Nail Syndrome. Skin appendage disorders. 2015 Mar;     [PubMed PMID: 27172293]

[18]

Itagaki H,Katuhiko S, Yellow nail syndrome following multiple orthopedic surgeries: a case report. Journal of medical case reports. 2019 Jul 1;     [PubMed PMID: 31256758]

[19]

Berglund F,Carlmark B, Titanium, sinusitis, and the yellow nail syndrome. Biological trace element research. 2011 Oct;     [PubMed PMID: 20809268]

[20]

Sarmast H,Takriti A, Yellow nail syndrome resulting from cardiac mitral valve replacement. Journal of cardiothoracic surgery. 2019 Apr 11;     [PubMed PMID: 30971303]

[21]

Wells GC, Yellow nail syndrome: with familiar primary hypoplasia of lymphatics, manifest late in life. Proceedings of the Royal Society of Medicine. 1966 May;     [PubMed PMID: 5933133]

[22]

Thomas PS,Sidhu B, Yellow nail syndrome and bronchial carcinoma. Chest. 1987 Jul;     [PubMed PMID: 3595241]

[23]

Gupta S,Samra D,Yel L,Agrawal S, T and B cell deficiency associated with yellow nail syndrome. Scandinavian journal of immunology. 2012 Mar;     [PubMed PMID: 21995335]

[24]

Siegelman SS,Heckman BH,Hasson J, Lymphedema, pleural effusions and yellow nails: associated immunologic deficiency. Diseases of the chest. 1969 Aug;     [PubMed PMID: 5822545]

[25]

Yalçin E,Doğru D,Gönç EN,Cetinkaya A,Kiper N, Yellow nail syndrome in an infant presenting with lymphedema of the eyelids and pleural effusion. Clinical pediatrics. 2004 Jul-Aug;     [PubMed PMID: 15248011]

[26]

Cebeci F,Celebi M,Onsun N, Nonclassical yellow nail syndrome in six-year-old girl: a case report. Cases journal. 2009 Oct 24;     [PubMed PMID: 19946476]

[27]

Jayaraj A,Raju S,May C,Pace N, The diagnostic unreliability of classic physical signs of lymphedema. Journal of vascular surgery. Venous and lymphatic disorders. 2019 Nov;     [PubMed PMID: 31281100]

[28]

King B, Diagnosis and management of lymphoedema. Nursing times. 2006 Mar 28-Apr 3;     [PubMed PMID: 16605153]

[29]

Novis SJ,Akkina SR,Lynn S,Kern HE,Keshavarzi NR,Pynnonen MA, A diagnostic dilemma: chronic sinusitis diagnosed by non-otolaryngologists. International forum of allergy     [PubMed PMID: 26750399]

[30]

Iqbal M,Rossoff LJ,Marzouk KA,Steinberg HN, Yellow nail syndrome: resolution of yellow nails after successful treatment of breast cancer. Chest. 2000 May;     [PubMed PMID: 10807848]

[31]

Brooks KG,Echevarria C,Cooper D,Bourke SC, Case-based discussion from North Tyneside General Hospital: somatostatin analogues in yellow nail syndrome associated with recurrent pleural effusions. Thorax. 2014 Oct;     [PubMed PMID: 24923874]

[32]

Norton L, Further observations on the yellow nail syndrome with therapeutic effects of oral alpha-tocopherol. Cutis. 1985 Dec;     [PubMed PMID: 4075838]

[33]

Tosti A,Piraccini BM,Iorizzo M, Systemic itraconazole in the yellow nail syndrome. The British journal of dermatology. 2002 Jun;     [PubMed PMID: 12072079]

[34]

Abell E,Samman PD, Yellow nail syndrome treated by intralesional triamcinolone acetonide. The British journal of dermatology. 1973 Feb;     [PubMed PMID: 4706464]

[35]

Arroyo JF,Cohen ML, Improvement of yellow nail syndrome with oral zinc supplementation. Clinical and experimental dermatology. 1993 Jan;     [PubMed PMID: 8440057]

[36]

Suzuki M,Yoshizawa A,Sugiyama H,Ichimura Y,Morita A,Takasaki J,Naka G,Hirano S,Izumi S,Takeda Y,Hoji M,Kobayashi N,Kudo K, A case of yellow nail syndrome with dramatically improved nail discoloration by oral clarithromycin. Case reports in dermatology. 2011 Sep;     [PubMed PMID: 22220146]

[37]

The diagnosis and treatment of peripheral lymphedema: 2013 Consensus Document of the International Society of Lymphology. Lymphology. 2013 Mar;     [PubMed PMID: 23930436]

[38]

Dallmann A,Attanoos RL, Yellow Nail Syndrome with Bilateral Pleural Plaques and Diffuse Pleural Thickening: A Mimic of Asbestos Related Disease. Case reports in pulmonology. 2018;     [PubMed PMID: 30345138]

[39]

Porcel JM, Pleural effusions from congestive heart failure. Seminars in respiratory and critical care medicine. 2010 Dec;     [PubMed PMID: 21213200]

[40]

Kaur R,Kashyap B,Bhalla P, Onychomycosis--epidemiology, diagnosis and management. Indian journal of medical microbiology. 2008 Apr-Jun;     [PubMed PMID: 18445944]

[41]

Daniels CE,Ryu JH, Improving the safety of thoracentesis. Current opinion in pulmonary medicine. 2011 Jul;     [PubMed PMID: 21346571]

[42]

Eid AA,Keddissi JI,Kinasewitz GT, Hypoalbuminemia as a cause of pleural effusions. Chest. 1999 Apr;     [PubMed PMID: 10208209]

[43]

Okajima S,Hirota A,Kimura E,Inagaki M,Tamai N,Iizaka S,Nakagami G,Mori T,Sugama J,Sanada H, Health-related quality of life and associated factors in patients with primary lymphedema. Japan journal of nursing science : JJNS. 2013 Dec;     [PubMed PMID: 24373443]

[44]

Mortimer PS, Swollen lower limb-2: lymphoedema. BMJ (Clinical research ed.). 2000 Jun 3;     [PubMed PMID: 10834903]

[45]

Ayata A,Unal M,Ersanli D,Bilge AH, Ocular findings in yellow nail syndrome. Canadian journal of ophthalmology. Journal canadien d'ophtalmologie. 2008 Aug;     [PubMed PMID: 18711477]

[46]

Bauer MA,Bauer KF,     [PubMed PMID: 25422998]