Beau’s Lines in Children - An Ignored Symptom

Introduction

Nails in infants and young children are thin and soft. Fingernails grow about 1.5 mm per day in children between 10 to 14 years. Nail disorders in children and infants are uncommon. Nail problems develop in 4.4 % of the pediatric population. If the nail issues develop, they are associated with systemic or psychological problems. This article reviews a condition called Beau’s line in children.

What Is Nail Anatomy?

Understanding the child’s nail anatomy is essential for understanding nail disease. A keratinized nail plate is attached to a vascularized nail bed at hyponychium, paronychium, eponychium, and cuticle. The cuticle is responsible for preventing foreign bodies from entering the nail matrix. The lunula is a visible distal portion of the nail matrix.

What Are Beau’s Lines?

These lines are grooves or dents and run from side to side in the fingernail or toenails. The Beau’s line appears as indentation or ridges on the nail plate. The nail can become discolored and appear yellow because of fungal infections. These lines can affect all nails, or just thumbs or big toes.

Beau’s lines can appear on multiple nails. As all the nails grow at the same rate, the length of nail depression in the nail plate provides information on the duration of causative factors affecting nail growth. For instance, ongoing or persistent factors result in deeper grooves, while transient causes result in shallower grooves. Children develop Beau’s line postnatally. Beau's line rarely occurs in older kids due to a high fever or zinc insufficiency.

What Causes Beau’s Line?

A clear cause for developing Beau’s lines in children has not been documented. The transient arrest of nail matrix production on the nail plate causes a transverse groove to form on the nail plate. It could result from interference with the nail’s blood supply or metabolism of the proximal nail matrix.

Another theory suggests that the matrix nail production remains intact, but a thinner and more dystrophic nail forms when the nail undergoes insult.

What Are the Risk Factors for Beau’s Lines?

The cause for Beau’s line is infections like:

• Hand-foot-mouth disease.

• Measles.

• Mumps.

• High fever.

• COVID-19.

• Streptococcus infection.

• Scarlet fever.

• Pneumonia.

• Malaria.

• Typhoid,

• Syphilis.

• Injuries or trauma to the nail matrix caused by a bone fracture and fingertip crush injury.

Other injuries like:

1. Dropping heavy objects on a finger or toe.

2. Extreme cold exposure.

3. Picking nails and cuticles repeatedly.

4. Nerve injuries following carpal tunnel syndrome, major surgeries, being cast or splint after fracture, and slamming fingers with the door cause Beau’s line.

Beau's line is brought on by cutaneous conditions such as psoriasis pustular, pemphigus vulgaris, paronychia, Steven Johnson syndrome, erythroderma, and reflex sympathetic dystrophy. Severe skin diseases damage the nail matrix. Diabetes, coronary thrombosis, myocarditis, hypopituitarism, hyperthyroidism, peripheral artery disease, Raynaud's disease, gout, hypertension, renal failure, epilepsy, and glomerulonephritis are examples of long-term health issues causing Beau’s line. It can interfere with blood flowing to the nail matrix.

Illnesses and severe stress can disrupt nail growth and make the body transiently direct energy from growing nails. Beau's line is brought on by extreme emotional or mental stress brought on by a divorce, a death in the family, and losing a job. Anxiety is another possible cause of developing the condition.

Chemotherapy drugs or medications such as:

• Radiation therapy.

• Retinoids.

• Carbamazepine.

• Cloxacillin.

• Dapsone.

• Metoprolol.

• Itraconazole.

• Azathioprine lead to Beau lines.

Beau lines appear quickly within two to three weeks after chemotherapy begins. Chemotherapy drugs are known to affect cells with a high turnover rate. Cuticles are where the nails grow, and cells have a high turnover rate. Therefore, these drugs cause a slowing down of cell growth rate and cause Beau’s lines. Therefore, these drugs cause a slowing down of cell growth rate and cause Beau’s lines.

Vitamin or nutrition deficiency disrupts nail growth. Severe zinc deficiency and lack of protein consumption result in Beau’s line, which resolves with proper nutrition consumption. In Kawasaki disease, children develop Beau’s line one or two months after fever onset.

Other risk factors are issues with nail fold, various systemic illnesses, and hypocalcemia.

How Is Beau’s Line Diagnosed?

Beau’s line can indicate systemic, recurrent, or severe insult or illness. Physical examination and their correlation with medical history help with diagnosis. One can determine the timing of the injury by measuring the distance between the proximal fold of the nail to Beau’s line. The angle of depression in the nail plate determines the severity of the causative factor. If there is a sharp angle, it indicates a fast onset, whereas a curved tip suggests a slower beginning.

A single Beau line on one nail suggests an injury that has affected a single finger or toe. If the lines form on all toes, it indicates illness or stress is a causative factor. Multiple lines show that the injury and trauma affected the nails more than once. Thicker Beau lines suggest that the injury or illness lasted for chronic periods.

What Is the Differential Diagnosis for Beau’s Line?

Differential diagnosis for Beau’s line include other types of Onychodystrophy. They are

1. Habit-tic deformity is a nail condition caused by repetitive trauma to the nail matrix.

2. The primary dermatologic inflammatory disorder could have nail symptoms.

3. Onychomadesis is a severe form of Beau’s line where there is the proximal separation of the nail plate from the nail bed.

4. Chronic paronychia can develop nail plate abnormalities similar to Beau’s lines.

5. Pohl-Pinkus constriction that affects hair can be a systemic cause of nail changes.

If the grooves form in multiple nails, it favors Beau’s line, but when a single nail is affected, it indicates other types of Onychodystrophy.

How Is Beau’s Line in Children Treated?

Beau’s line is not a disease and is not harmful by itself. Treatment of underlying causes can help resolve Beau’s line. Once the treatment for the underlying cause begins, it takes three to six months to regrow so the ridge can be removed.

1. As these lines are a temporary modification to nail plate morphology, continued nail growth and nail plate formation help in problem resolution.

2. For chemotherapy patients, the resolution of Beau lines can take longer. Specific treatment for Beau’s line is not necessary.

3. Individuals with eczema or psoriasis that develop Beau’s line need treatment with creams and moisturizers.

4. Diabetic patients must maintain their sugar levels. Children with peripheral artery disease require medication or surgery.

Conclusion

Beau lines can appear as the physiologic alteration in 92 % of newborns after four weeks and disappear before 14 weeks. It can also develop because of underlying pathology or risk factors in older children. A single transverse depression of the finger or toenail develops. There is no specific treatment for Beau’s line as it is not a pathological condition with harmful consequences.