Relationship of Hair Regrowth Pattern in Alopecia Areata Patches According to DIMT Classification with Treatment Modalities and Patch Size: A Retrospective Cross-Sectional Analysis

Abstract

Background The morphology of hair regrowth in alopecia areata (AA) patches could be classified into four types, namely diffuse, irregular, marginal, and targetoid patterns, according to the DIMT classification. However, factors affecting hair regrowth patterns have not been investigated. Objective We investigated whether the DIMT-classified hair regrowth patterns of AA patches are associated with treatment modality and patch size. Methods We conducted a retrospective, cross-sectional study of 152 AA patches with hair regrowth. Results The associations between the diffuse pattern and patch size >2 cm ( p =0.006; odds ratio [OR]: 0.36, 95% confidence interval [CI]: 0.17~0.74), between the irregular pattern and triamcinolone acetonide intralesional injection ( p <0.001; OR: 274.87, 95% CI: 25.75~2,933.56), between the marginal pattern and systemic and topical corticosteroid ( p =0.018; OR: 4.89, 95% CI: 1.31~18.27), and between the targetoid pattern and patch size >2 cm ( p =0.028; OR: 2.50, 95% CI: 1.10~5.68) were statistically significant. Conclusion Treatment modalities and patch size are the factors affecting hair regrowth patterns in AA patches.

The alopecia areata donut sign. Evidence of synchronous hair growth in adult humans

“…Plikus et al also observed that late anagen follicles cannot induce anagen re-entry even when next to competent telogen regions. 5 The concepts of refractory and competent telogen can be used to explain why in alopecia totalis, IICS can induce regrowth of small tufts, without inducing a regenerative wave. The observation that late anagen follicles do not signal neighbouring follicles can be used to explain the finding of 1 or 2 individual fibres on a scalp with alopecia totalis.…”

“…8 Overexpression of noggin, in mouse skin, resulted in a markedly shortened refractory phase and faster propagation of the regenerative wave. 5 Understanding the hair cycle dynamics and controls can help clinicians optimize AA treatments and ponder the future potential of Noggin and BMP-2 as therapeutic targets for hair growth.…”

“…4 There have been various AA regrowth patterns described, including diffuse, irregular, marginal and targetoid. 5 However, a common clinical observation of AA regrowth following IICS into an expanding patch of AA is what we term the 'donut sign' (Figure 1). This is not seen in stable AA patches and only occurs when the patch of hair loss is still expanding at the time of IICS.…”