A retrospective study on the clinical characteristics and prognosis of alopecia totalis and universalis: An update on prognosis

Alopecia totalis (AT) and alopecia universalis (AU) is known to have a poor prognosis with high relapse rate, and treatment failure is observed in most patients, regardless of the type of therapy. Although treatment and the prognosis of AT and AU have improved in recent years, old data are routinely cited in recent review papers without questioning them. The authors aimed to study the clinical characteristics and prognosis of AT and AU to update and compare the results with those of previously reported studies. The authors retrospectively reviewed patients diagnosed with AT and AU from 2006 to 2017 in a single institution. Of the 419 patients, the mean age at first episode was 22.9 years, and 24.6% had early onset (≤13 years). During follow‐up, 53.9% had more than 50% hair growth, and 19.6% of patients showed >90% hair growth. Among patients who showed >50% improvement, 36.7% had no recurrence. In early studies conducted in the 1950s and 1960s, the chance of full hair regrowth was reported to be <10%. In our study, patients with >90% improvement in AT and AU accounted for 19.6% of patients. The authors provide an update on data regarding the prognoses of AT and AU.


| INTRODUC TI ON
Alopecia areata (AA) is a common nonscarring alopecia with autoimmune etiopathogenesis. 1 Its pathogenesis is complex and genetic susceptibility has been proposed in a previous study. 2It tends to affect children and young adults more frequently but can present at any age. 3Approximately 5% of cases progress to alopecia totalis (AT) or alopecia universalis (AU), which are the subtypes of AA with the worst prognosis. 4They pose a therapeutic challenge and may have a devastating effect on quality of life. 5In cases of hair regrowth, relapse is expected, although a minority of patients may achieve a long-term response. 1 early studies conducted in the 1950s and 1960s, the chance of full hair regrowth was reported to be <10%. 6However, old prognostic data on AT and AU do not reflect the efficacy of current therapeutic modalities. 7 this study, we aimed to better assess the long-term evolution of patients with AT and AU and reevaluate clinical characteristics and predictors of prognosis by conducting a retrospective study with follow-up of patients with AT and AU from our institution.
We retrospectively reviewed patients diagnosed with AT and AU from 2006 to 2017 at Kyung Hee University Hospital at Gangdong, who had a follow-up time of ≥24 months.The study was approved by the institutional review board.Epidemiological, clinical, and therapeutic variables were collected.AA severity was assessed using the Severity of Alopecia Tool (SALT) score according to the Alopecia Areata Investigational Assessment Guideline criteria: S0 (no hair loss), S1 (<25%), S2 (25%-49%), S3 (50%-74%), S4 (75%-99%), and S5 (100%) hair loss. 8The latest (most recent) SALT was taken for the calculation of prognosis.If there was fluctuation, the most recent episode was taken into consideration.For statistical purposes, we defined "good prognosis" as patients with hair growth >90%, and "poor prognosis" was defined as patients with hair growth <25% during follow-up.
We analyzed the differences between two groups classified according to prognosis using Mann-Whitney test.

| Clinical characteristics of 419 patients with AT/AU
A total of 419 patients who were diagnosed with AT or AU between 2006 and 2017 had a follow-up duration of ≥24 months.The patients were followed for a mean of 5.1 years (range, 2-11 years).Among them, 78 (18.6%) were diagnosed with AU.The mean age at onset was 25.8 years (range, 0-60 years).The mean time between the presentation of AA and development of AT or AU was 14.8 months (range, 0.3-72 months) (Table 1).

| Prognosis of 419 patients with AT/AU
Among patients who showed improvement >50%, 36.7% (83/226) had no recurrence, and this was well-maintained even after discontinuing treatment.Recurrence was defined as no recurrence during the long-term follow-up period after treatment cessation.
Patients who had a good prognosis (>90% hair growth) had a later first onset (26.8 vs 24.6 years, p = 0.012) and a shorter duration of the current episode (3.3 vs 3.8 years, p = 0.004) than patients with a poor prognosis.There were no statistically significant differences in episode number, sex, or family history between the two groups (Table 2).

| DISCUSS ION
This study reports the largest series of patients with AT and AU describing the specific data of important value to clinicians when informing patients about their prognosis.
During the follow-up period, complete hair growth was observed in 9.1% of patients, and 19.6% of patients had >90% hair growth.Among patients with improvement >50%, 36.7% had no recurrence during follow-up, and this was well-maintained even after treatment discontinuation during the regular clinic visits.The overall prognosis improved more than that of previous reports, which seems to be due to the existence of more diverse treatment modality than in the past, with regular long-term follow-up visits in our institution. 7 a long-term follow-up study of 191 patients with AA, no patient achieved full hair growth who had AU, and only one patient had full recovery from AT. 9 The cosmetically acceptable hair regrowth rate (≥90% hair regrowth) was 24.2% (17 of 70 patients) in a study by Jang et al., 7 which is similar to the current study (19.6%).
Our study had the largest number of patients diagnosed with AT and AU regarding the long-term prognosis of severe forms of AA.
This vast list further supports the reported improved prognosis of AT and AU.
Regarding comorbidities, 15.3% of patients with any form of AA had a coexistent autoimmune condition, with an incidence consistent with a previous study. 10Several studies demonstrated a high rate of thyroid disease in patients with AA. [10][11][12][13] We recommend including thyroid evaluation in the workup of patients with extensive AA.
Our study had a retrospective design and there was potential bias in the assessment of the effectiveness of the treatments (some patients were treated concomitantly with oral and topical therapies).
However, the objective of the study was not to evaluate the effec-

CO N FLI C T O F I NTE R E S T S TATE M E NT
None declared.Abbreviations: AA, alopecia areata.a "Good prognosis" defined as patients with hair growth >90% during the follow-up period.

Sang-Min
b "Poor prognosis" defined as patients with hair growth <25% during the follow-up period.
TA B L E 2 Comparison of characteristics between patients with good and poor prognosis.
tiveness of different therapies for AT, but to describe the clinical and epidemiological features, therapeutic response, and prognostic factors in a large series of patients diagnosed with extensive AA and AT/ AU.Due to the retrospective nature of the study, after the patient was discharged, further clinical information regarding recurrence was not collected.Our recurrence data may have discrepancies from the real recurrence rates.Contemporary data regarding long-term sequelae and factors associated with outcomes in patients with AT and AU are sparse.In our study, we propose an update on the prognosis of AT/AU.We also suggest age of the first episode and duration of the current episode as prognostic factors in extensive AA and AT/AU.ACK N OWLED G M ENTS This work was supported by the National Research Foundation of Korea grant funded by the Korean government (MSIT) (number 2019R1A2C1089788).