Early detection of microcomedones induced by cocoa butter using reflectance confocal microscopy

Abstract

Background Many ingredients used in cosmetics evoke a comedogenic response. The concept of ‘‘acne cosmetica’’ was developed to link the use of certain ingredients to comedone formation. Various clinical research methods have been suggested for the effective screening of an ingredient that can worsen acne or acneiform eruption and confirm its clinical relevance as to whether it is used as a non‐comedogenic claim. Although comedogenicity assessment has not yet been established, attempts have been made to evaluate the comedogenicity of cosmetic ingredients and find the most appropriate method to evaluate comedogenicity in human skin. Materials and methods Total 6 participants were included in the study. Each participant received patches on the upper back containing cocoa butter. We used reflectance confocal microscopy (RCM) to count the number of microcomedones and follicles induced by cocoa butter. Results The mean value change of microcomedone/follicle by the comedogenic substance was significantly higher than that of the non‐applied site for 2 weeks (p = 0.0419). The mean value changes of the microcomedone diameter caused by the comedogenic substance were significantly larger than those found at the non‐applied site at 2 and 4 weeks (p = 0.0026 and p = 0.0038, respectively). Conclusions We recommend RCM as a non‐invasive real‐time method that is useful for evaluating comedogenicity and early detection of a microcomedone.

Honokiol Improves Acne-like Lesions in a Rabbit Ear Model by Alleviating Hyperkeratosis and Sebum Secretion

“…Summarizing the above research, we found that honokiol could act on all causes of comedone formation. In addition, the microcomedone, a small comedone that is invisible to the naked eye, 21 is considered to be the cornerstone of the pathogenesis and treatment of acne. 22 Therefore, if microcomedones are effectively treated, acne can be controlled.…”

Confocal microscopy and optical coherence tomography of inflammatory skin diseases in hairs and pilosebaceous units: A systematic review

“…The 39 studies included concerned the following 10 skin diseases: 14 studies of acne vulgaris, [7][8][9][10][11][12][13][14][15][16][17][18][19][20] nine studies of rosacea, [21][22][23][24][25][26][27][28] four studies of alopecia areata, [30][31][32][33] two studies of HS, 35,41 two studies of folliculitis, 34,42 two studies of folliculitis decalvans, 43,44 two studies of lichen planopilaris, 33,45 two studies of discoid lupus erythemasus, 33,46 one study of frontal fibrosing alopecia 47 and one including one patient with keratosis pilaris. 48 In total, 33 RCM studies, 12 OCT studies and 45 combined.…”

“…Acne vulgaris [7][8][9][10][11][12][13][14][15][16][17][18][19][20] Comedos demonstrate enlarged infundibula with a bright onion ringlike border. Papules poorly defined with bright inflammatory infiltrates extending into dermis.…”

“…Post-treatment a reduction of hyperkeratinized follicles, comedos, papules, pustules, inflammation and increase of normal-appearing follicles and epidermal thickness In OCT, closed and open comedos were characterized by an enlarged infundibula including bright hyperkeratinization of border. 7,14,[16][17][18]36 In RCM, closed comedos showed well-defined infundibula with thick bright borders [8][9][10][11][12][13][14]16,17,19 and open comedos showed larger infundibula with irregular borders filled with amorphous material and multiple bright dots. In papules, RCM showed inflammatory infiltrates, ill-defined borders, perifollicular hyper-vascularity and infundibular hyperkeratosis.…”

“…RCM allows real-time visualization of skin layers at almost histologic resolution to a depth of 200-300 micrometres. 5 RCM easily detects inflammatory cells and content of hair follicles in vivo and has previously been used to explore hair and skin diseases including acne vulgaris, [7][8][9][10][11][12][13][14][15][16][17][18][19][20] rosacea, [21][22][23][24][25][26][27][28][29] alopecia areata [30][31][32][33] and Malassezia folliculitis. 34 OCT visualizes cross-sectional details of skin layers and hairs to a depth of 1-2 mm and has previously been used to explore acne vulgaris, 7,14,[16][17][18] rosacea 29 and HS.…”