Alopecia areata is an autoimmune disorder that disturbs the immune privilege of hair follicles 11. The disruption of immune privilege in hair follicles leads to the infiltration of CD4 + and CD8 + T cells and the release of Th1 cytokines, which contribute to the autoimmune phenomenon and subsequent hair loss 6. Apart from the treatment guidelines published in 2003 by MacDonald Hull et al., there are currently no universally accepted or widely recognized standard treatment guidelines for alopecia areata 12.
In the current study, a significant decrease in SALT score was found after AA treatment with topical calcipotriol for 3 months. The result concurs with Molinelli et al., Narang et al., and Abd-ElRaheem et al who found that the use of calcipotriol resulted in accelerated hair regrowth and a greater proportion of patches exhibiting a complete response 13, 14,9.
In opposition, Cerman et al. noticed that the efficacy of topical calcipotriol in AA is weak with an average of 27% total hair regrowth 15.
The observed outcomes could be attributed to the biological effects of VIT D3 derivatives, which encompass the control of proliferation, maturation of epidermal cells, and adjustment of cytokine production 16.
The current study showed a significant decrease in SALT score among patients treated by intra-lesion PRP every 2 weeks. this may be explained by the release of vascular endothelial growth factor from the α-granule of platelets is vital for the process of angiogenesis associated with the growth phase of hair follicles.
Similarly, Albalat, and Ebrahim, Shumez et al., and Balakrishnan et al also found that there was a rapid improvement after 12 weeks of treatment with intra-lesion PRP 17, 18, 19
This outcome contrasts with Gupta et al. who reported that PRP has limited efficacy in the treatment of chronic AA 20.
This difference is due to the decreased number of PRP sessions in the Gupta et al. study compared with our study in which patients received 6 sessions during 3 months against 3 sessions only in the Gupta et al. study.
Using a combination of topical calcipotriol and intra-lesion PRP demonstrated a significant decrease in SALT score. Our study revealed that there is a significant reduction in group III (combined topical calcipotriol and PRP) then group II (PRP) then group I (topical calcipotriol).
Our study didn't find a significant difference in the microscopic signs between the 3 groups of AA patients. The yellow dots sign was common in the three groups with a percentage of 69.2%,76.2%, and 84.6% respectively.
Guttikonda et al., and Chiramel et al also reported that the yellow dots sign was a common feature in their study with a percentage of 88%, and 87.5% respectively 21 22.
Otherwise, Kibar et al. noticed that the incidence of yellow dot signs was low at 23. Inui et al. also found that the prevalence of yellow dots was 63% the difference is that due to the yellowish skin color commonly found in Asian patients, it can be challenging to visually detect the presence of yellow dots 24.
Our study is through with Chiramel et al., and Amer et al who demonstrated that the incidence of black dots was 79.5%, and 75% respectively 22, 25
On the other hand, Inui et al., and Bapu et al. noticed that black dots were presented in 44%, and 36% respectively 24, 26
The exclamation mark sign is considered a pathognomonic sign in AA 27. The current study uncovered that the proportion of the exclamation mark sign was 69.2% in Group I, 61% in Group II, and 84.6% in Group III.
This result concurs with Rakowska et al. who found that the incidence of exclamation marks in his study was 68% 28.
In divergence from Mane et al. who noticed that exclamation mark sign was uncommon with a rate of 12% in his study 29.
The presence of black dots, tapering hairs, and broken hairs was found to be positively correlated with disease activity. This finding accounts for the variations observed in different studies 29.
Short villous hair was prevalent in this study. In group I, 92% of the hair was short and villous, while in group II, it accounted for 84%, and in group III, it constituted 69%. This finding goes along with Kibar et al. and Chiramel et al. who found that shot villous hair was common in their studies 23,22.
The current study showed that credibility hair was seen by a frequency of 61.5% in group I, 61.5% in group II, and 53.8% in group III.
Rudnicka et al., in our study, observed that coudability hair was seen in 12–42% of cases 30.
Pigtail hairs were observed in 46.2% of individuals in group I, 30.8% in group II, and 38.5% in group III. Our findings align with those of Amer et al., who documented the presence of pigtail hairs in 25% of patients with alopecia areata. 25