Diffuse Alopecia

Diffuse alopecia is reversible hair loss that occurs in a generalized manner throughout the scalp. Hair loss occurs homogeneously due to the reduction in the size of the hair follicles, causing the hair to become finer and more fragile as a consequence of an underlying disease.

The process is classified into two types depending on its duration. While acute diffuse alopecia resolves within six months, the disease is considered chronic when it persists for more than six months.

The healthy hair growth cycle consists of three phases: anagen (growth), catagen (transition), and telogen (resting or shedding). Depending on the follicular phase in which it occurs, there are two types of diffuse alopecia:

• Anagen diffuse alopecia: hair falls out while in the growth phase.
  • Acute anagen effluvium: follicular activity stops as a consequence of medical treatment (drugs, chemotherapy), leading to the loss of up to 90% of the hair after several days.
  • Chronic anagen effluvium: this is a rare condition that predominantly affects blonde girls. The hair shaft has poor adherence to the follicle, so the hair is easily pulled out. It usually resolves spontaneously over the years.
• Telogen diffuse alopecia: hair is lost during the shedding phase.
  • Acute telogen effluvium: occurs approximately three months after the triggering event, which is usually surgery, stress, or an infection.
  • Chronic telogen effluvium: usually associated with metabolic or nutritional disorders. It persists with fluctuations for several years.
  • Immediate anagen release effluvium: hair rapidly shifts from the growth phase to the shedding phase as a consequence of disease or severe stress.
  • Delayed anagen release effluvium: the growth phase is prolonged during periods of hormonal changes, such as the postpartum period.

The prognosis for diffuse alopecia is generally good, as hair regrows once the disease that caused the hair loss resolves. Although it is usually a transient condition, early detection is essential to reverse its progression with a greater guarantee of success.

Symptoms

The most characteristic symptoms of diffuse alopecia are:

• Hair miniaturization: the hair becomes progressively finer and of poorer quality.
• Reduced hair density: volume and density decrease, as the hair becomes straighter and drier.
• Rapid hair loss throughout the scalp, without affecting body hair in other areas. Hair shedding, especially during certain seasons or stressful periods of life, may be concerning without necessarily indicating a disease. A patient is only considered to have alopecia when losing more than 100 hairs per day.
• Visible scalp in advanced stages: when the process is advanced, the scalp begins to become visible.

Unlike other types of alopecia, diffuse alopecia does not present scaling, irritation, itching, or inflammation of the scalp skin.

Causes

The most common causes of diffuse alopecia are:

• Physical stress: severe illnesses, infections, or surgical procedures.
• Emotional stress: anxiety, depression.
• Hormonal imbalances: the most common are pregnancy, postpartum, menopause, hypothyroidism, and hyperthyroidism.
• Certain medications, such as anticoagulants, chemotherapy drugs, or medications used to treat hypertension.
• Autoimmune diseases.
• Nutritional deficiencies: deficiencies in iron, zinc, vitamin B, or protein may contribute to alopecia.

Hair loss usually occurs between two and four months after the triggering factor, which may make diagnosis more difficult.

Risk Factors

Factors that increase the risk of developing diffuse alopecia include:

• Sex: women are usually more prone due to hormonal fluctuations throughout life (pregnancy, postpartum, menopause, polycystic ovary syndrome). Nevertheless, it is also common in men.
• Iron-deficiency anemia: iron deficiency.
• Strict diets leading to nutritional deficiencies.
• Severe illnesses, surgeries, high fever, anxiety, or bereavement situations causing physical or emotional stress.
• Systemic diseases, meaning diseases that affect the entire body.
• Overuse of chemical hair products.

Complications

Diffuse alopecia may lead to the following complications:

• Significant psychological impact: anxiety, low self-esteem, depression, social isolation.
• Scalp hypersensitivity.
• Increased risk of photoaging or skin cancer due to greater scalp exposure.

Prevention

Maintaining a healthy lifestyle and good hair care habits is the best way to prevent diffuse alopecia, although it cannot always be avoided. The main recommendations include:

• Following a balanced diet rich in proteins, minerals, and vitamins.
• Exercising regularly.
• Maintaining a healthy sleep routine.
• Managing stress whenever possible.
• Correcting hormonal imbalances under the supervision of a specialist physician.
• Properly caring for and washing the hair and scalp.
• Gentle daily hair brushing.
• Protecting the scalp from sun exposure.
• Avoiding tight hairstyles, excessive heat exposure, and the use of harsh chemical products (hair dyes, straightening treatments, perms).

What specialist treats diffuse alopecia?

Diffuse alopecia is treated within the specialty of Medical-surgical dermatology and Venereology.