Levels of evidence (I-IV) and grading of recommendations (A-E) are defined at the end of the "Major Recommendations" field.
Diagnosis
The diagnosis of alopecia areata is usually straightforward although the following may cause diagnostic difficulties:
- Trichotillomania: this condition probably causes most confusion and it is possible that it coexists with alopecia areata in some cases. The incomplete nature of the hair loss in trichotillomania and the fact that the broken hairs are firmly anchored in the scalp (i.e. they remain in the growing phase, anagen, unlike exclamation mark hairs) are distinguishing features
- Tinea capitis: the scalp is inflamed in tinea capitis and there is often scaling but the signs may be subtle.
- Early scarring alopecia
- Telogen effluvium
- Anagen effluvium (drug-induced) may mimic diffuse alopecia areata
- Systemic lupus erythematosus
- Secondary syphilis
Occasionally, alopecia areata presents as diffuse hair loss which can be difficult to diagnose. The clinical course often reveals the true diagnosis but a biopsy may be necessary in some cases.
Investigations
Investigations are unnecessary in most cases of alopecia areata. When the diagnosis is in doubt appropriate tests may include:
- Fungal culture
- Skin biopsy
- Serology for lupus erythematosus
- Serology for syphilis
The increased frequency of autoimmune disease in patients with alopecia areata is probably insufficient to justify routine screening.
Management
An overriding consideration in the management of alopecia areata is that, although the disease may have a serious psychological effect, it has no direct impact on general health that justifies the use of hazardous treatments, particularly of unproven efficacy. In addition, many patients, although by no means all, experience spontaneous regrowth of hair.
Counselling
An explanation of alopecia areata, including discussion of the nature and course of the disease and the available treatments, is essential. Some patients are profoundly upset by their alopecia and may require psychological support. Contact with other sufferers and patient support groups may help patients adjust to their disability. The decision to treat alopecia areata actively should not be taken lightly. Treatment can be uncomfortable for the patient, time consuming and potentially toxic. It may also alter the patient's attitude to their hair loss. Some patients find it difficult to cope with relapse following or during initially successful treatment and they should be forewarned of this possibility. These considerations are particularly important in children where the social disruption and focusing of the child's attention on their hair loss, which may result from active treatment, have to be weighed carefully against the potential benefits. On the other hand, some patients are appreciative that something has been tried, even if it does not work.
Summary of Treatment Recommendations
Alopecia areata is difficult to treat and few treatments have been assessed in randomized controlled trials. The tendency to spontaneous remission and the lack of adverse effects on general health are important considerations in management, and not treating is the best option in many cases. On the other hand, alopecia areata may cause considerable psychological and social disability and in some cases, particularly those seen in secondary care, it may be a chronic and persistent disease causing extensive or universal hair loss. In those cases where treatment is appropriate there is reasonable evidence to support the following:
- Limited patchy hair loss: Intralesional corticosteroid. (B III)
Intralesional corticosteroids stimulate hair regrowth at the site of injection. The effect is temporary, lasting a few months, and it is unknown whether the long-term outcome is influenced.
- Extensive patchy hair loss: Contact immunotherapy (B II-ii)
- Alopecia totalis/universalis (AT/AU): - Contact immunotherapy (B II-ii).
- Topical steroids used under occlusion (17.8% long-term response) (B II-i)
Contact immunotherapy is the best-documented treatment in severe alopecia areata but it is not widely available, involves multiple visits to hospital over several months, and stimulates cosmetically worthwhile hair regrowth in <50% of patients with extensive patchy hair loss. It is the only treatment likely to be effective in AT/AU although the response rate in such patients is even lower. It may cause troublesome temporary local inflammation but serious side effects are rare. 2,3-diphenylcyclopropenone [DPCP] is susceptible to degradation by ultraviolet light and needs to be protected from light during storage and by covering the skin after application
Potent topical corticosteroids and, to a lesser extent, dithranol and minoxidil lotion, are widely prescribed by dermatologists for limited patchy alopecia areata, and are safe, but there is no convincing evidence that they are effective.
Continuous or pulsed systemic corticosteroids and psoralen plus ultraviolet A (PUVA) have also been used to treat alopecia areata. However, in view of the potentially serious side effects and inadequate evidence of efficacy, none can be recommended at this time.
Children may be treated in a similar fashion to adults. However, intralesional corticosteroids are often poorly tolerated and many clinicians are reluctant to use aggressive treatments such as contact immunotherapy in children.
Definitions:
Levels of Evidence
I: Evidence obtained from at least one properly designed, randomized controlled trial
II-I: Evidence obtained from well designed controlled trials without randomization
II-ii: Evidence obtained from well designed cohort or case-control analytic studies, preferably from more than one centre or research group
II-iii: Evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled experiments (such as the introduction of penicillin treatment in the 1940s) could also be regarded as this type of evidence.
III: Opinions of respected authorities based on clinical experience, descriptive studies, or reports of expert committees
IV: Evidence inadequate owing to problems of methodology (e.g., sample size, or length or comprehensiveness of follow-up or conflicts of evidence)
Recommendation Grades
- There is good evidence to support the use of the procedure.
- There is fair evidence to support the use of the procedure.
- There is poor evidence to support the use of the procedure.
- There is fair evidence to support the rejection of the use of the procedure.
- There is good evidence to support the rejection of the use of the procedure
