Alopecia areata


  • Alopecia areata is a common autoimmune disease causing patchy hair loss.
  • It is diagnosed based on the clinical picture.
  • Patients have an increased risk of other autoimmune diseases.
  • Response to treatment varies. Spontaneous periods of recovery are typical.

Epidemiology and pathophysiology

  • Alopecia areata is a common disease causing patchy hair loss.
  • Its lifetime prevalence in Europe is about 2%, and it has increased over the past few decades.
  • Immunological factors are important for its pathogenesis.
    • The immunological tolerance of hair follicles decreases for reasons remaining unclear, and this triggers an autoimmune reaction. As a result of this, hair follicles stop working but are not destroyed.
  • There may be hereditary factors predisposing to the disease; cases are often seen in the near family.
  • Triggering factors include infections, medication and psychosocial stress, for example.


  • Clinically, there are typically one or more round, asymptomatic, bald patches on the scalp (> 90%; pictures (Alopecia areata) (Alopecia areata) (Diffuse alopecia areata) (Alopecia areata)) or other places on the skin (< 10%; e.g. beard, thighs, genital area).
  • There is typically fine, light vellus hair at the margins of such patches.
  • The patches are usually asymmetrically situated, of different sizes and shapes.
  • There is no erythema, scarring or scaling.
  • The patches typically develop within a few weeks. The course of disease in an individual patient is hard to predict.
  • Patients may simultaneously have small depressions on their finger and/or toe nails.
  • Patients with alopecia areata have been found to more commonly have atopic eczema, vitiligo, psoriasis, hypothyroidism, inflammatory bowel diseases and rheumatoid arthritis (than the population without alopecia areata).
  • Severe clinical pictures
    • Alopecia totalis complete or near complete hair loss on the scalp
    • Alopecia universalis (picture (Alopecia universalis)): loss of all or nearly all body hair, including for example eyelashes, eyebrows and hair on the body and the limbs
    • Ophiasis: symmetric, band-like loss of hair at the hairline, such as the occipital or temporal areas
    • Sisaipho: hair loss mainly centrally at the top of the head; may occur in streaks; the hairline is normal.
    • Acute diffuse and total alopecia (ADTA)
    • Canities subita (Marie Antoinette or Thomas More syndrome): sudden whitening of the hair on the scalp and/or the body

Differential diagnosis

  • Male (Hair loss and balding) or female pattern (Hair loss and balding) hair loss (androgenetic alopecia): hair thinning in typical areas; cases frequently occur in near relatives, too.
  • Telogen or anagen hair loss (Hair loss and balding): diffuse hair loss all over the scalp; the cause can usually be identified in the patient history (such as an infection, childbirth, medication).
    • Telogen hair loss occurs with a delay of several months.
  • Tinea capitis : a scaly, erythematous patch on the scalp; more common in children, has become rarer
  • Trichotillomania is due to irresistible hair pulling. In places, the hair may be of the length of a buzz cut; wounds and hematomas can be seen on the scalp.
  • Traction alopecia: hair loss for mechanical reasons (hairstyle, combing, etc.); often in the frontal hairline.
  • Scarring alopecias, such as lichen ruber planus (Lichen planus) (lichen planopilaris) or lupus erythematosus (systemic [SLE] (Systemic lupus erythematosus (SLE)) or cutaneous discoid lupus (Discoid lupus erythematosus)) may cause scarring patchy hair loss; there is erythema and scaling as well as pain and itching on the scalp.
  • Secondary syphilis (Syphilis): causes multiple small, asymptomatic hairless patches on the scalp; check local epidemiology.


  • Diagnosis is based on the clinical picture. Dermatoscopy (Dermatoscopy) (trichoscopy) used by an experienced examiner can improve diagnostic accuracy.
  • Some patients may have vitamin D deficiency; 25(OH)D should be tested, as necessary.
  • Differential diagnostic tests may include:
    • Samples for fungal testing (native microscopy, fungal culture) to exclude tinea
    • Skin biopsy (histological examination and, as necessary, immunofluorescence test)
    • Antibody tests, such as Treponema pallidum antibodies, antinuclear antibodies
    • Other systemic or autoimmune diseases can be sought case by case depending on the symptoms: free T4, TSH, TPOAb, fasting plasma glucose, HbA1c, faecal calprotectin, RF, citrulline peptide antibodies.
    • Patients may have underlying psychiatric disorders that can be screened using various scales; depression, for example (Recognition and diagnostics of depression).


  • Treatment is not usually decisive for the prognosis but it may increase hair growth to some extent.
  • It is important for patients to understand that the disease is not dangerous for their somatic health.
  • Any benefits or harms of treatment should be discussed with the patient.
  • Treatment should be chosen together with the patient, considering cosmetic distress, the severity and extent of the disease, any risk factors the patient may have, and what is available at the treating unit.
  • It is often enough for patients to hear that the disease is benign and to wait for spontaneous recovery.
  • Patients with severe alopecia areata can be reimbursed for a wig as a medical rehabilitation aid. Check local policies.
  • Herbal medicinal products, vitamins, trace elements, etc. have not been proved to help.
  • Mild clinical pictures (a few single patches)
    • Topical potent or very potent glucocorticoid solutions in courses of 1–3 months, for example
    • 5% minoxidil solution in long courses of 3–12 months
    • Glucocorticoid injections have also been used.
      • Triamcinolone acetonide, for example, diluted with saline solution up to 2.5–10 mg/ml. Intradermal injections are given very superficially at distances of about 1 cm from each other in doses of 0.1–0.2 ml, no more than 20 mg per session. Treatment can be repeated every 4–12 weeks, as necessary. The possibility of dermal atrophy with pitting must be kept in mind.
    • Dermatologists sometimes use sensitization based on producing contact allergy (topical DCPC treatment with diphenylcyclopropenone).
  • Severe clinical pictures
    • Systemic treatments guided by dermatologists (such as JAK inhibitors) have also been used but the benefits and risks of such treatments must be considered case by case.


  • Patches may heal spontaneously, usually within several months. Some 30–50% of individual patches heal within a year.
  • After recovery, the disease may recur.
  • In more severe clinical pictures, response to treatment is often limited and the prognosis of hair regrowth is rather poor. In alopecia universalis and totalis, spontaneous healing is rare.

Specialist consultation

  • A dermatologist should be consulted in severe cases, when considering systemic treatments, in diagnostically unclear cases and whenever scarring alopecia is suspected.


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