Think of your scalp as an extension of your facial skin—in fact, scalp is the second most sensitive area on your head, just after the eye contour. It's the vital "soil" from which your hair grows, home to more than 100,000 follicles and a rich supply of nerves and blood vessels. Today, with the rising quality of life, people place a greater emphasis on skin care, with (scalp care also encompassed). Since the scalp and hair significantly influence facial and overall aesthetics, the interest in scalp wellness is surging. Consequently, finding effective ways to assess scalp health has become a pressing need.

Indicators for Scalp Health Evaluation

Guided by the Expert Consensus on Scalp Health Management [1], CIRS Testing evaluates the scalp health across five parameters, including:

• Dandruff;
• Sebum levels;
• Itchiness;
• The presence of redness/bumps/pustules; and
• The overall hair status.

Figure 1: Indicators for Scalp Health Evaluation

In this article, we will introduce the evaluation methods for dandruff, sebum levels and the itchiness.

I. Evaluation Methods for Dandruff

Dandruff becomes visible when aggregates of shed stratum corneum cells exceed 0.2 mm in diameter; while smaller clusters cannot be seen by the naked eye.

The primary causes of dandruff are as follows:

Infection- or Disease-Related Scalp Inflammation [1]: Including pityriasis simplex capitis, seborrheic dermatitis, psoriasis, tinea capitis, and atopic dermatitis.

Impaired Skin Barrier Function [2]: Damage to the scalp's natural barrier disrupts scalp hydration, which can also lead to the dandruff.

Imbalance in Scalp Microbiome [3]: Dandruff is associated with an imbalance in scalp microbiome, with a decrease in Cutibacterium acnes and an overgrowth in Malassezia restricta and Staphylococcus.

The evaluation methods cover:

1. Trichoscope (with visualized images)

Figure 2: Dandruff levels 48 hours after shampooing

2. Intelligent Scalp Analyzer (with visualized images)

Figure 3: Dandruff images at hair root 48 hours after shampooing

3. Collecting dandruff flakes to measure the quantity, area percentage, and particle size distribution (quantitative analysis and visualized images can be provided).

Figure 4: Shed dandruff images 48 hours after shampooing

4. Use the DermaLab Combo, Tewameter TM Nano, and Skin-pH-Meter PH905 to quantitatively analyze the scalp hydration, TEWL and the PH value.

Figure 5: Scalp Barrier Function Analyzer

5. Scalp Microbiome Analysis

Figure 6: Scalp Microbiome Composition

II. Evaluation Methods for Scalp Sebum Level

Abnormal scalp sebum is classified into seborrhea and sebum deficiency. Seborrhea manifests as an oily, greasy scalp and hair with increased scaling. In contrast, sebum deficiency presents with a dry scalp and hair.

The evaluation methods cover:

1. Use Meibometer MB 560 to analyze the scalp sebum (quantitative analyze results can be provided)

Figure 7: Scalp Sebum Measurement

2. Intelligent Scalp Analyzer (with visualized images)

Figure 8: Scalp Sebum Distribution

III. Evaluation Methods for Scalp Itchiness

Scalp itching arises from a combination of pathophysiological mechanisms and imbalances in scalp microbiome.

Pathophysiological mechanisms include:

Cutaneous: This type of itch is triggered by direct skin issues including inflammation, dryness, or damage. These problems initiate a cascade of chemical mediators (e.g., histamine, proteases, Substance P), which activate local nerve endings. The resulting electrical signal then journeys to the brain, where it is perceived as the sensation of itchiness.

Neuropathic: This type of itch stems directly from damage or disease affecting the sensory nerve pathways.

Neurogenic: This type of itch is generated within the central nervous system, despite no evidence of actual nerve damage.

Psychogenic: This type of itch is primarily associated with psychological factors, including chronic stress or other psychiatric disorders.

Scalp Microbiome Dysbiosis: An overgrowth of the Malassezia yeast is strongly linked to itchiness.

The evaluation methods cover:

1. 3S (Sensitive Scalp Score) Questionnaire [5]

Figure 9: Sensitive Scalp Score Questionnaire

The 3S questionnaire serves as a preliminary screening tool to help identify potential scalp sensitivity. However, it should be filled in under the guidance of a professional to avoid inaccuracies resulting from participant misinterpretation.

2. After collecting sample with D-Squame tape, histamine content is determined using High-Performance Liquid Chromatography (HPLC) or Enzyme-Linked Immunosorbent Assay (ELISA) (Quantitative analytical results can be provided).

Figure 10: Scalp Histamine Content

3. Scalp Microbiome Measurement

Our Advantages

Extensive Participants Database: owns a extensive participants database which spans multiple cities across the country, assembling a diverse group of participants with varied consumer needs. This ensures CIRS Testing to meet the broad requirements of different brands in market research, thereby providing comprehensive and authentic consumer feedback for product efficacy evaluation.

Perfect Laboratory Construction: possesses a full set of professional testing equipment, including dermatoscopes, needle-type moisture test probes, ultra-small transepidermal water loss test probes, and scalp sebum meters. By integrating the expert assessments from dermatologists with various technical approaches, we offer extensive efficacy evaluation services for hair care products.

Whole Industry Chain Services: provide one-stop services covering the whole life-cycle of a personal care product, which includes cosmetic ingredient development, physical/chemical tests, toxicological tests (in vivo & in vitro), efficacy studies (in vivo & in vitro), ingredient registration, and product registration.

Our team

CIRS Testing Cosmetic Laboratory has been accredited by the China National Accreditation Service for Conformity Assessment (CNAS) and China Metrology Accreditation (CMA). It is also accredited by the National Medical Products Administration.

With complete equipment and excellent technical competence, CIRS Testing Cosmetic Laboratory received recognition for its testing capabilities both at home and abroad. The Cosmetic Laboratory has created many patents, and has maintained close cooperation and in-depth communication with many national laboratories.

CIRS Testing Cosmetic Team is comprised of a marketing team, customer service team, regulatory compliance team as well as the laboratory, with a total of more than 60 staff. The team keeps on enhancing technical skills and improving its cosmetic service system. It is able to provide a one-stop service to clients, including cosmetic regulations consulting, registration/filing, safety efficacy evaluation, and testing.

If you have any needs or questions, please contact us at cosmetic-ck@cirs-group.com.

References

[1] 李春英, 肖嵘, 刘玮, 等. 头皮健康管理专家共识[J]. 中华皮肤科杂志, 2022, 55(10): 843-849.

[2] 吴文育, 林尽染, 杨蓉娅. 中国头皮抗衰专家共识[J]. 实用皮肤病学杂志, 2020, 13(6): 321-325.

[3] Saxena R, Mittal P, Clavaud C, et al. Comparison of Healthy and Dandruff Scalp Microbiome Reveals the Role of Commensals in Scalp Health[J]. Frontiers in Cellular and Infection Microbiology, 2018, 8: 1-15.

[4] Xu Z, Wang Z, Yuan C, et al. Dandruff is associated with the conjoined interactions between host and microorganisms[J]. Scientific Reports. 2016, 6: 1-9.

[5] Misery L, Rahhali N, Ambonati M, et al. Evaluation of sensitive scalp severity and symptomatology by using a new score[J]. Journal of the European Academy of Dermatology & Venereology, 2011, 25(11): 1295-1298.[6] Szepietowski J, Kerr K, Schwartz J, et al. Scalp Stratum Corneum Histamine Levels: Novel Sampling Method Reveals Association with Itch Resolution in Dandruff/Seborrhoeic Dermatitis Treatment[J]. Acta Derm Venereol, 2011, 91(4): 404-408.