Beau's Lines

Are You Confident of the Diagnosis?

What you should be alert for in the history

A variety of causes including systemic illnesses and medications can cause this phenomenon.

Characteristic findings on physical examination

Beau’s lines are a nonspecific physical finding on the nail plate (Figure 1). They represent a transient arrest of nail matrix production of nail plate, resulting in a transverse groove within the nail plate. Usually multiple nails are affected. Since the nails grow at the same rate, the length of the depression in the nail plate can give a clue as to the duration of the systemic issue that was affecting nail growth. For example, a more sustained illness would correspond to a longer groove, while a short-lived issue would result in a shorter groove.

Figure 1.

Beau’s lines.

The timing of the insult can be estimated by measuring the distance from the proximal nail fold to the Beau’s line, as fingernails grow approximately 0.1mm per day. Additionally, it has been suggested that the angle of the depression in the nail plate can be proportional to the severity of the causative factor. A sharp angle would suggest a fast onset, whereas a more curved angle would suggest a more slowly evolving process.

Diagnosis confirmation

The diagnosis is usually made through physical examination and correlation with the medical history, which may shed light on a possible instigating event. The differential diagnosis could include other forms of onychodystrophy, such as a habit-tic deformity, or primary dermatologic inflammatory disorders affecting the nail unit. The presence of multiple affected nails supports the diagnosis of Beau’s lines, whereas changes limited to a single nail would favor another cause for the onychodystrophy.

Who is at Risk for Developing this Disease?

A variety of systemic and cutaneous disorders and medication use can cause Beau’s lines. Some sytemic entities that have been associated with the development of Beau’s lines include coronary thrombosis, myocarditis, hypopituitarism, hyperthyroidism, gout, diabetes mellitus, hypertension, epilepsy, renal failure, and glomerulonephritis. Beau’s lines have also been associated with the presence of a high fever.

Infections including Kawasaki disease, hand-foot-mouth disease, measles, mumps, scarlet fever, pneumonia, malaria, typhoid fever, and syphliis have been associated with Beau’s lines. Many medications have been associated with the development of Beau’s lines, including systemic chemotherapeutic agents, retinoids, dapsone, metoprolol, itraconazole, octreotide, and azathioprine.

Cutaneous disorders have also been associated with Beau’s lines, including eczema, pustular psoriasis, pemphigus vulgaris, paronychia, telogen effluvium, alopecia areata, Stevens Johnson syndrome, toxic epidermal necrolysis, erythroderma, and reflex sympathetic dystrophy. Trauma, including that from a manicure, bone fracture, fracture and immobilization, and fingertip crushing injury have all been associated with Beau’s lines. Beau’s lines have been reported in association with deep saturation dives and time spent at high altitudes.

What is the Cause of the Disease?

A clear pathophysiology for the cause of Beau’s lines has not been established. It has been speculated that the temporary arrest of nail matrix production of nail plate is caused by an interference with the blood supply and the metabolism of the proximal nail matrix. Another postulated mechanism is that the matrix nail plate production remains intact, but a thinner and more dystrophic nail plate is produced during the time of the systemic insult.

Systemic Implications and Complications

Observation of Beau’s lines could indicate an ongoing systemic illness, a recurrent illness, or a significant systemic illness or insult that has since resolved. A thorough medical history to evaluate for new medications or systemic stressors could identify an underlying association. The patient’s primary care physician can assist with a thorough physical examination and additional review of systems if no associated cause can be identified.

Treatment Options

Beau’s lines can be a clue to a systemic illness or drug reaction. If a systemic illness, medication, or other causative factor is identified, this underlying issue should be treated. The Beau’s lines themselves represent a transient modification in the nail plate morphology and should grow out with continued production of nail plate. Additional interventions aside from the tinture of time are not required for treatment of Beau’s lines.

Optimal Therapeutic Approach for this Disease

When Beau’s lines are diagnosed, the focus should be on a comprehensive medical history and physical examination to search for an associated systemic abnormality. The Beau’s lines themselves do not have a specific treatment, and if the systemic issue resolves, should not be a persistent problem.

Patient Management

If an associated precipitating event is identified to be related to the Beau’s lines, additional follow-up for the Beau’s lines is not required.

Unusual Clinical Scenarios to Consider in Patient Management

If no precipitating factor is identified, and the nail changes persist over time, consideration of other entities in the differential diagnosis of onychodystrophy should be considered. Onychomadesis could be considered a severe form of Beau’s lines, where there is proximal separation of the nail plate from the nail bed. Additionally, patients with chronic paronychia can demonstrate nail plate abnormalities resembling Beau’s lines, given the episodic insults the nails receive.

The presence of a concurrent Pohl-Pinkus constriction in the hair further supports a systemic cause for the nail changes. The Pohl-Pinkus constriction is caused by a temporary systemic insult in which hair follicle production is transiently diminished, resulting in a hair shaft with a focally diminished bore.

What is the Evidence?

Avery, H, Cooper, H, Karim, A. “Unilateral Beau's lines associated with a fractured olecranon”. Australasian J Dermatol. vol. 51. 2010. pp. 145-6. (After a fall a 14-year-old boy sustained a right olecranon fracture, which was treated with open reduction of the fracture and internal fixation with tension band wiring, followed by immobilization in a cast. He developed Beau's lines on all fingers on his right hand except the thumb. The authors speculate the Beau's lines could have been caused by the fracture itself or by subsequent immobilization. The article contains a comprehensive listing of causes of Beau's lines.)

Lee, Y, Yun, S. “Unilateral Beau's lines associated with a fingertip crushing injury”. J Dermatol. vol. 32. 2005. pp. 914-6. (A 36-year-old man sustained a thumb-crushing injury from a container box and developed Beau's lines on all five fingers of the same hand 6 weeks after the injury. The fingertip was amputated, but no other injuries were noted to the other fingers. A variety of causes could be responsible, including physiologic changes accompanying the injury, immobilization of the hand, and use of a tourniquet during an operation to repair the finger.)

Clementz, G, Mancini, A. “Nail matrix arrest following hand-foot-mouth disease: A report of five children”. Pediatr Dermatol. vol. 17. 2000. pp. 7-11. (Five children from the Chicago suburbs developed Beau's lines after being diagnosed with hand-foot-mouth disease by a physician. This article also describes several possible physiologic mechanisms for the development of Beau's lines.)

Chen, H, Liao, Y. “Beau's lines associated with itraconazole”. Acta Derm Venereol. vol. 82. 2002. pp. 398(A 61-year-old patient developed Beau's lines on all fingernails and toenails after starting treatment with continuous itraconazole therapy for onychomycosis.)

Makhzoumi, Z, Decapite, T, Gaspari, A. “Development of Beau's lines in two patients receiving azathioprine”. J Dermatol Treat. vol. 20. 2009. pp. 246-7. (Two patients were noted to develop Beau's lines associated with hypersensitivity reaction to azathioprine. The first patient was treated for pemphigus vulgaris and the second patient for Wegner's granulomatosis.)

Schwartz, H. “Clinical observation: Beau's lines on fingernails after deep saturation dives”. Undersea Hyperb Med. vol. 33. 2006. pp. 5-10. (The author reports his experience of 8 of 12 divers developing Beau's lines following deep saturation dives at the Ocean Simulation Facility of the Navy Experimental Diving Unit in Panama City, Florida. During the dives, the divers performed hard work on bicycle ergometers.)

Harford, R, Cobb, M, Banner, N. “Unilateral Beau's lines associated with a fractured and immobilized wrist”. Cutis. vol. 56. 1995. pp. 263-4. (This article describes a case of a 13-year-old boy who developed unilateral Beau's lines after wearing two separate casts for a total of 8 weeks as treatment for a fracture of the metaphysis of the radius. Three to four weeks after the second cast was removed, Beau's lines were noticed on the nail plates of all five fingers of the affected hand.)

Bellis, F, Nickol, A. “Everest nails: a prospective study on the incidence of Beau's lines after time spent at high altitude”. High Alt Med Biol. vol. 6. 2005. pp. 178-80. (A prospective study of mountain climbers in eastern Nepal had 52 responders evaluated after 8 weeks of follow-up; 17 of 52 (33%) developed Beau's lines at the 8-week follow-up time point. There was no evidence of a relationship between Beau's lines and maximum altitude reached, minimum oxygen saturation, duation of various levels of hypoxia, worst acute mountain sickness score, use of acetazolamide, or length of stay above 4000m.)

Williamson, PJ, de Berker, D. “Pohl-Pinkus constrictions of hair following chemotherapy for Hodgkin's disease”. Br J Haematol. vol. 128. 2005. pp. 582(This report describes a good example of a 30-year-old patient who developed both Beau's lines and Pohl-Pinkus constrictions of the hair after treatment for Hodgkin's disease.)