Evaluation of sensitive scalp severity and symptomatology by using a new score

Sensitive Scalp and Trichodynia: Epidemiology, Etiopathogenesis, Diagnosis, and Management

Sensitive scalp (SSc) is considered a sensitive skin on the scalp, with its particularities. Although it is not rare in the dermatological practice and the term is commonly present in personal care products, this entity is poorly investigated in the medical literature. The etiopathogenesis is still uncertain, and the sensitivity may be associated with hair loss. Clinical manifestations are subjective symptoms of pruritus, burning, pain, pricking, and/or trichodynia, often with scalp erythema. SSc can be triggered by several factors (endogenous or exogenous). The diagnosis is guided by the anamnesis, and there are still no specific trichoscopic features. Trigeminal trophic syndrome and postherpetic neuralgia are the main differential diagnosis to be considered. We organized the therapeutical approach in three steps: scalp care, topical and systemic treatment.

Effects of a Postbiotic Saccharomyces and Lactobacillus Ferment Complex on the Scalp Microbiome of Chinese Women with Sensitive Scalp Syndrome

Introduction

Sensitive scalp is one of the most frequent complaints related to sensitive skin syndrome, characterized by unpleasant sensory reactions in the absence of visible signs of inflammation. In this study, the effects of topical application of postbiotic Himalaya-derived Saccharomyces and Lactobacillus ferment complex (SLFC) on the bacterial and fungal scalp microbiome at the taxonomic level and alleviation of sensitive skin syndrome were investigated.

Methods

Firstly, healthy female participants (aged 30-45) were classified into a healthy scalp group and a sensitive scalp group based on the questionnaire. Thereafter, topical application of SLFC on sensitive scalp as well as scalp microbiome was evaluated, with the difference in the distribution of microbial taxa between healthy and sensitive scalp communities was assessed using 16S rRNA and ITS1 sequencing analysis. In addition, the effect of SLFC on scalp microbiome at the species level for Cutibacterium acnes, Staphylococcus epidermidis, and Malassezia restricta was evaluated by the qPCR assessment.

Results

After treatment with SLFC for 28 days, the abundance of Staphylococcus, Lawsonella, and Fusarium in the sensitive scalp group was highly significantly increased (p < 0.001), while the abundance of Cutibacterium and Malassezia was highly significantly decreased (p < 0.001). Furthermore, the self-assessment questionnaire indicated a syndrome alleviation effect of 100% after 28 days with a twice-daily application of the SLFC.

Discussion

The obtained results would help to better understand the microbial community of the sensitive scalp and provide useful information on utilization of SLFC for maintaining a healthy scalp and modulating the scalp microbiome.

Cowhage-induced itch scores and the current perception threshold in assessing sensitive skin: An observational laboratory study

BACKGROUND

The diagnosis of sensitive skin remains nonuniform, and the underlying mechanism is unclear. Previous studies were inconsistent in the current perception threshold (CPT) measurement for sensitive skin; thus, the neural sensitivity of sensitive skin needs to be clarified.

OBJECTIVES

This study aimed to compare the CPT measurement and the cowhage test for sensitive skin and to investigate the correlation between CPT values and cowhage-itch scores.

METHODS

Participants with and without sensitive skin (n = 30, 30) were included. The cowhage test and CPT measurement with its related sensations were performed.

RESULTS

No difference was found in CPT between the sensitive and nonsensitive groups at either the site of the face or the forearm (5, 250, or 2000 Hz). Once the CPT was reached, sensations (itch, stinging, and throbbing) were significantly different between the two groups. Cowhage provoked more intense itch with a longer duration in the face (visual analog scale [VAS] score 1.90 ± 1.47 vs. 0.52 ± 0.90, p < 0.001; duration 3.80 ± 3.31 vs. 0.87 ± 1.43 min, p < 0.001) and forearm (VAS 2.53 ± 2.60 vs. 0.72 ± 1.06, p < 0.001; duration 3.37 ± 3.46 vs. 1.33 ± 2.14 min, p < 0.01) of the sensitive group compared with the nonsensitive group. Cowhage-induced itch and CPT-related itch (5 Hz) showed moderate correlations in both the face (r = 0.441, p < 0.001) and forearm (r = 0.491 p < 0.001) and weak correlations in the forearm (r = 0.323 at 250 Hz, p = 0.012; r = 0.376 at 2000 Hz, p = 0.003).

CONCLUSIONS

Cowhage test showed better performance in assessing the neural sensitivity of sensitive skin in comparison with the CPT measurement. Evaluation of CPT-related sensations may add valuable information to sensitive skin assessment.

[Translated article] Sensitive Scalp: Diagnosis and Practical Management

Sensitive scalp is sensitive skin located on the scalp. Sensitivity is considered primary in the absence of an associated scalp disorder and secondary when caused by conditions such as psoriasis, seborrheic dermatitis, and atopic dermatitis. The clinical manifestations of primary sensitive scalp are subjective. Common presenting symptoms are burning, itching, trichodynia, and dysesthesia, often coinciding with hair loss. Clinically, the skin appears normal or red. An objective diagnosis based on laboratory or histologic findings is not possible. Triggers may be endogenous (e.g., stress and emotional or psychopathological disturbances) or exogeneous (e.g., topical products and cosmetics). Treatment must be individualized. Options include pimecrolimus, hydration with hyaluronic acid, and mesotherapy with plasma rich in growth factors.

Sensitive Scalp: Diagnosis and Practical Management

Sensitive scalp is sensitive skin located on the scalp. Sensitivity is considered primary in the absence of an associated scalp disorder and secondary when caused by conditions such as psoriasis, seborrheic dermatitis, and atopic dermatitis. The clinical manifestations of primary sensitive scalp are subjective. Common presenting symptoms are burning, itching, trichodynia, and dysesthesia, often coinciding with hair loss. Clinically, the skin appears normal or red. An objective diagnosis based on laboratory or histologic findings is not possible. Triggers may be endogenous (e.g., stress and emotional or psychopathological disturbances) or exogeneous (e.g., topical products and cosmetics). Treatment must be individualized. Options include pimecrolimus, hydration with hyaluronic acid, and mesotherapy with plasma rich in growth factors.

Itchy scalp

Itchy scalp troubles many people. The causes of itching can be systemic, psychogenic, neurological, and dermatological diseases. The most common dermatological diseases associated with scalp itching are seborrheic dermatitis and psoriasis. The pathogenesis of these diseases is very different, but in both cases, skin microbiota changes may present, supporting the inflammation. Also, in both conditions, flaking and other similar clinical presentations occur. In addition to adequate therapy, the choice of care product is important. For a patient with scalp disease, the specialist should recommend shampoo and other products that can complement the basic therapy. Such products should have some features: they should help to normalize the microbiota and pH, relieve inflammation, and eliminate unpleasant symptoms, including itching. One such product is LE SANTI shampoo, which shows good clinical efficacy for several dermatological diseases.

Sensitive Skin Syndrome: A Low-Noise Small-Fiber Neuropathy Related to Environmental Factors?

Background and Objectives

Patients frequently complain of mild, transient, unpleasant skin sensations that cannot be diagnosed as common neuropathies. Dermatologists have termed these symptoms “sensitive skin syndrome.” This narrative review was performed for a better knowledge by other specialists.

Databases and Data Treatment

Publications on pain in sensitive skin syndrome were obtained from PubMed.

Results

There is a growing body of data supporting the concept that sensitive skin is a type of small-fiber neuropathy. The arguments are based on clinical data, a decrease in intra-epidermal nerve fiber density, quantitative sensory testing abnormalities and an association with irritable bowel syndrome and sensitive eyes. Sensitive skin is triggered by environmental factors. Sensitive skin is a frequent condition, with a lifetime prevalence of ~50% according to self-reports.

Conclusions

Mild levels of skin pain or itch are frequently experienced by patients, who rarely report them. There is a need for a better knowledge of sensitive skin because it can be the first level of small-fiber neuropathies.

Sensitive scalp: an epidemiologic study in patients with hair loss

Sensitive scalp is a common condition defined by the presence of erythema and/or subjective symptoms as pain, pricking, burning, pruritus of the scalp elicited by triggering factors. Trichodynia is a term that describes a sensation of pain or burning of the scalp and was assumed to be part of sensitive scalp. Main goal of the study was to establish the prevalence of sensitive scalp in patients with trichological disorders. We conducted a retrospective observational study recorded: age, sex, trichological disorder (telogen effluvium, androgenetic alopecia, alopecia areata, scarring alopecia, trichotillomania) and scalp symptoms (pruritus, pain, burning and itching sensation). We studied 317 patients. 102 patients (32%) complained of sensitive scalp. Telogen effluvium patients had a significantly higher prevalence of sensitive scalp (p <0.001), pain (p= 0.028), burning sensation (p=0.018), pruritus (p=0.016) and trichodynia (p<0.001) than other patients with alopecias. Likewise, AA patients had a statistically significant higher prevalence of pruritus (p=0.0256) and trichodynia (p=0.0223) than other alopecias patients. Sensitive scalp is a frequent symptom reported by patients with hair loss. Telogen effluvium and alopecia areata seem to be most associated to sensitive scalp.

Burden of Sensitive Skin (BoSS) Questionnaire and Current Perception Threshold: Use as Diagnostic Tools for Sensitive Skin Syndrome

The assessment of sensitive skin syndrome, characterized by subjective unpleasant sensations, remains a challenge, since there is no international consensus on the best diagnostic tools. This study evaluated the combination of the Burden of Sensitive Skin (BoSS) questionnaire and the current perception threshold as diagnostic tools for sensitive skin syndrome, and the relationship between BoSS and the subjects’ smoking status, phototype and skin type. A total of 100 women completed the BoSS questionnaire, and current perception threshold was measured on the face. The BoSS score was significantly higher in the self-reported sensitive skin group compared with the non-sensitive skin group (25.61 vs 14.05; p < 0.001), and in non-smokers vs smokers (23.00 vs 18.37; p < 0.05). In addition, the current perception threshold values were similar between the sensitive and non-sensitive groups. These results suggest that BoSS is a better diagnostic tool for sensitive skin syndrome than the current perception threshold, and that smokers less frequently have sensitive skin than do non-smokers.

Understanding the Sensitive Skin Subject to Achieve a More Holistic Diagnosis

Sensitive skin Syndrome (SSS) is a complex global clinical phenomenon that is defined by the self-reported presence of different sensory perceptions, including tightness, stinging, burning, tingling, pain and pruritus and often without objective signs. Due to the subjective nature of this clinical condition, the diagnosis is complex and there is often a disconnect between what subjects feel and what medical professionals can observe. This chapter reviews the known underlying physiology, some of the triggering factors associated with SSS, co-morbidities as well as the psychological impact on individuals suffering from this condition. The goal is to bridge the gap between the physicians’ understanding and the subjects’ perceptions of this real-life condition that affects so many.

The Impact of Shampoo Wash Frequency on Scalp and Hair Conditions

BACKGROUND

How frequently should the scalp and hair be cleansed? A dearth of objective data has led to confusion both among lay people and experts. Each extreme has potential detrimental effects: overcleaning may lead to surface damage while undercleaning may lead to buildup of harmful stimuli. This situation is complicated because both objective and subjective criteria are relevant to assess optimal cleaning.

OBJECTIVES

The objective of this work was to combine epidemiological and treatment data with both objective and subjective end points to yield clear data to guide both the consumer and expert as to optimal scalp and hair cleaning practices.

METHODS

Two studies were conducted with Asian populations without any specific scalp pathologies. An epidemiological study was conducted as a function of natural wash frequency. This was combined with a controlled wash frequency study. In both cases, objective measures of hair and scalp condition were assessed. These were combined with self-assessments of all participants.

RESULTS

In the epidemiological study, it was observed that overall satisfaction with hair and scalp condition was achieved when washing 5-6 times per week. This was consistent for both objective and subjective end points. Controlled treatment likewise showed that a daily wash regimen was superior to once per week cleansing for all end points. No objective detrimental effects to hair at this level of cleansing were observed.

CONCLUSIONS

Two different studies led to the same conclusion: higher wash frequency is both beneficial and more preferred to lower wash frequency among the Asian populations studied. Concerns related to "overcleaning" were unfounded both objectively and subjectively.

Sensitive Scalp: A Possible Association With the Use of Hair Conditioners

A sensitive scalp is defined by the occurrence of unpleasant sensations (tingling, burning, pain, pruritus) triggered by stimuli that should not cause such sensations. Environmental factors, particularly cosmetics, can be triggering factors. The aims of this study were to assess hair cosmetic product consumption in subjects with sensitive scalp and to perform a clinical evaluation of sensitive scalp. After a dermatological examination, women between the ages of 18 and 65 years with or without a sensitive scalp completed different questionnaires. Their use of hair cosmetics (frequency, amount per application) was recorded. A total of 160 women with a mean age of 41 years were included. Twenty-seven subjects presented with seborrheic dermatitis or psoriasis, so only 133 were included in the analysis. Five percent of the subjects declared they had a very sensitive scalp, 25% had a sensitive scalp, 38% had a slightly sensitive scalp, and 32% had a scalp that was not sensitive. The mean sensitive scalp score (3S) score was 3.7 ± 1.6 in the very sensitive scalp group, 3.6 ± 2.1 in the sensitive group, 1.2 ± 1.2 in the slightly sensitive group and 0.1 ± 0.4 in the non-sensitive group. Two groups were analyzed: the 56 subjects with a sensitive scalp (3S ≥ 2 score) and the 56 subjects with a null 3S score. In the sensitive scalp group, 89% suffered from itch, and 45% suffered from tingling. No parameter (hormonal status, smoking, age, phototype, BMI) was associated with the 3S score. No differences in the exposure to shampoos and masks between the two groups were noted. The exposure to hair conditioners was significantly higher in the sensitive scalp group than in the group without sensitive scalp. Itch is the main symptom of a sensitive scalp. The frequency of a sensitive scalp was lower than that previously described when the subjects with scalp dermatosis were excluded. The amount of hair conditioners used was significantly higher in subjects with sensitive scalp than in those without sensitive scalp, suggesting a possible link.

Scalp involvement in patients referred for patch testing: Retrospective cross-sectional analysis of North American Contact Dermatitis Group data, 1996 to 2016

BACKGROUND

Scalp conditions are often multifactorial.

OBJECTIVE

To characterize patients with scalp involvement and patch-testing outcomes.

METHODS

Retrospective cross-sectional analysis of North American Contact Dermatitis Group data (1996-2016). Study groups included patients with scalp involvement (≤3 anatomic sites coded) with or without additional sites.

RESULTS

A total of 4.8% of patients (2331/48,753) had scalp identified as 1 of up to 3 affected anatomic sites. Approximately one-third of "scalp-only" individuals had a specific primary diagnosis of allergic contact dermatitis (38.6%), followed by seborrheic dermatitis (17.2%) and irritant contact dermatitis (9.3%). When adjacent anatomic sites were affected, allergic contact dermatitis was more frequently identified as the primary diagnosis (>50%). The top 5 currently clinically relevant allergens in scalp-only patients were p-phenylenediamine, fragrance mix I, nickel sulfate, balsam of Peru, and cinnamic aldehyde. Methylisothiazolinone sensitivity was notable when adjacent anatomic sites were involved. The top 3 specifically identified sources for scalp-only allergens were hair dyes, shampoo/conditioners, and consumer items (eg, hair appliances, glasses).

LIMITATIONS

Tertiary referral population.

CONCLUSION

Isolated scalp involvement was less likely to be associated with allergic contact dermatitis than when adjacent anatomic sites were involved. Overlap with multiple diagnoses was frequent, including seborrheic dermatitis, irritant dermatitis, other dermatoses, or all 3. p-Phenylenediamine was the most common allergen.

Sensitive Skin in the Genital Area

When evaluating sensitive skin, it is common to focus on the face. However, it is becoming increasingly clear that individuals can have different perceptions about the degree of skin sensitivity at distinct anatomic sites. Structural variations in the skin of different body sites can contribute to differences in barrier function, which may contribute to differences in skin sensitivity. Potential triggering factors for skin sensitivity would be expected to vary by body site. For example, the face is exposed to all ambient environmental conditions in the course of daily life, and to several products (e.g., cosmetics for women) and practices (e.g., shaving for men) that may lead to adverse sensations associated with sensitive skin. In contrast, the skin of the genital area is protected from ambient environmental conditions. However, the genital area can be exposed to conditions of higher temperature, different habits and practices and moisture due to the semi-occlusive environment. For some individuals, additional challenges such as incontinence can provide triggering factors for skin sensitivity that effect only the genital area. This article reviews data on the perception of sensitive skin of the genital area, differences based on gender, age, racial differences, and the effects of incontinence on skin sensitivity. The effects of menopause are also considered with regards to sensitive skin perceptions and to emerging differences in biomolecular and physical measures of the urogenital skin.

The Prevalence of Sensitive Skin

Sensitive skin has been described as unpleasant sensory responses to stimuli that should not provoke such sensations. Objectively measurable signs of irritation are not always present in individuals with sensitive skin, however, subjective sensory effects such as, itching, burning, stinging, tightness, and dryness, are consistently present. Given the subjective nature of the phenomenon known as sensitive skin, surveys have been a popular approach to evaluating the prevalence of this condition among the general population, and a number of them have been conducted worldwide. Overall, ~60–70% of women and 50–60% of men report having some degree of sensitive skin. However, there are differences between populations in various geographies, and perceptions of sensitive skin at specific anatomic sites. This article is a review of survey data on the prevalence of self-declared sensitive skin in various geographies, among different gender and age groups, and at various anatomic sites. In addition, we review the factors that may contribute to sensitive skin, and the physiological characteristics associated with this condition, including impaired barrier function and heightened neural reactions.

Scalp Pruritus: Review of the Pathogenesis, Diagnosis, and Management

Scalp pruritus is a frequent problem encountered in dermatological practice. This disorder is caused by various underlying diseases and is a diagnostic and therapeutic challenge. Scalp pruritus may be localized to the scalp or extended to other body areas. It is sometimes not only associated with skin diseases or specific skin changes, but also associated with lesions secondary to rubbing or scratching. Moreover, scalp pruritus may be difficult to diagnose and manage and may have a great impact on the quality of life of patients. It can be classified as dermatologic, neuropathic, systemic, and psychogenic scalp pruritus based on the potential underlying disease. A thorough evaluation of patients presenting with scalp pruritus is important. Taking history and performing physical examination and further investigations are essential for diagnosis. Therapeutic strategy comprises removal of the aggravating factors and appropriate treatment of the underlying condition. All treatments should be performed considering an individual approach. This review article focuses on the understanding of the pathophysiology and the diagnostic and therapeutic management of scalp pruritus.

Sensitive scalp is associated with excessive sebum and perturbed microbiome

BACKGROUND

Sensitive scalp, one of the most frequent complaints among sensitive skin syndrome, has been described as abnormal and unpleasant sensory reactions of the scalp to environmental stimulus. However, the symptoms are usually objective and hard to diagnose.

OBJECTIVE

This study aimed to reveal the biophysical properties and etiology of sensitive scalp.

METHODS

Sixty-two healthy female subjects were enrolled and divided into nonsensitive scalp (NS) and sensitive scalp (SS) groups according to questionnaires. Noninvasive instruments were used to measure biophysical properties. Ultra-performance liquid chromatography-tandem mass spectrometry and gas chromatography mass spectrometry were introduced to quantify skin lipids profiles, and 16S rRNA sequencing was used to detect the composition of bacteria.

RESULTS

Sensitive scalp showed elevated pH level, more irritated skin, and more fluorescence of porphyrins. Increased sebum production was found in SS group at occiput, among which free fatty acids, cholesteryl ester, and squalene were significantly in higher amount compared with NS. SS also had significantly higher percentage of Propionibacterium, and lower bacterial diversity.

CONCLUSIONS

Taken together, sensitive scalp showed disrupted barrier function, abnormal sebum amount and composition, as well as perturbed microbiome, which might be the direct cause. Products targeting these features could be helpful for the treatment of sensitive scalp.

Scalp Itch: A Systematic Review

Scalp itch is a frequent complaint in the dermatological setting. It is common for the dermatologist to encounter patients with no evident cause of scalp pruritus, making it a distressing situation for both the clinician and the patient. The aim of this paper is to propose a systematic approach to scalp itch, which classifies scalp pruritus into two types: (1) with or (2) without dermatological lesions, and presence or absence of hair loss. Also, it is important to think first about the most common causes and then rule out other, less common etiologies. The acronym SCALLP and the five steps for scalp evaluation (listen, look, touch, magnify, and sample) are useful tools to keep in mind for an assertive approach in these patients.

Sensitive skin

Sensitive skin is a clinical condition defined by the self-reported facial presence of different sensory perceptions, including tightness, stinging, burning, tingling, pain and pruritus. Sensitive skin may occur in individuals with normal skin, with skin barrier disturbance, or as a part of the symptoms associated with facial dermatoses such as rosacea, atopic dermatitis and psoriasis. Although experimental studies are still pending, the symptoms of sensitive skin suggest the involvement of cutaneous nerve fibres and neuronal, as well as epidermal, thermochannels. Many individuals with sensitive skin report worsening symptoms due to environmental factors. It is thought that this might be attributed to the thermochannel TRPV1, as it typically responds to exogenous, endogenous, physical and chemical stimuli. Barrier disruptions and immune mechanisms may also be involved. This review summarizes current knowledge on the epidemiology, potential mechanisms, clinics and therapy of sensitive skin.

Evaluation of the severity and triggering factors of sensitive scalp in Chinese females

BACKGROUND

Sensitive scalp which has been recently proposed and assessed by several questionnaires is one of the most cosmetic concerns in sensitive skin syndrome by consumers.

OBJECTIVE

This study is to investigate the prevalence and factors related to the scalp sensitivity in China.

METHODS

Two well-known questionnaires including four-grade self-assessment and 3S, and a new questionnaire we proposed (10Q), were used to evaluate the severity and symptoms of sensitive scalp.

RESULTS

The proportions of sensitive scalp according to self-assessment and 3S were 35.77% and 57.45%, respectively. Distributions of severity and tendency of proportion along ages were significantly different between the two methods. The 10Q questionnaire which we designed could discriminate different grade of severity of sensitive scalp with superior reliability. Moreover, triggering factors which have significant impacts on the symptoms of sensitive scalp were elucidated by logistic regression analysis, including air dryness, exercises, humidity, heat, and sun.

CONCLUSION

Questionnaires with more dimensions and details such as 10Q and 3S should be used for the diagnosis, prognosis, and treatment monitoring on sensitive scalp in Chinese female.

Highly efficient and compatible shampoo for use after hair transplant

Background

Sensitive or hyperreactive skin is a common condition defined by prickling, burning, pain, and pruritus. Although this skin problem was initially described on the face, the scalp is often affected. A sensitive scalp can react with irritation to harsh surfactants or other additives which are often present in shampoos. For this reason, we developed a new rinse-off hypertolerant shampoo specifically designed for the hypersensitive and problematic scalp.

Methods

The shampoo formulation is based on an extremely mild surfactant system and contains bisabolol, an anti-irritant and anti-inflammatory ingredient of chamomile. The shampoo is free of additives such as perfumes, silicones, colorants, parabens, paraffins, and betaine. Since skin can remain in a hyperreactive state after wounding, the status after hair transplantation was chosen as a model system to test the shampoo. Scalp condition and compatibility of each volunteer were analyzed by a plastic surgeon directly after hair transplant and after stitch removal. The plastic surgeons also rated whether they would recommend the further use of the test shampoo. Additionally, volunteers completed a self-assessment questionnaire.

Results

Following hair transplantation, regular use of the shampoo resulted in a significant reduction in the extent of scabbing and erythema. This was confirmed by dermatological scalp examinations performed by the plastic surgeon as well as in volunteers’ self-assessments. The plastic surgeon highly recommended the further use of the test shampoo after hair transplant to all study participants.

Conclusion

Application of the test shampoo demonstrated excellent skin compatibility and product efficacy after hair transplant. The test shampoo significantly reduced the extent of scabs and erythema. Therefore, the shampoo is ideally suited for use after hair transplantation and for the treatment of sensitive scalp. The excellent skin compatibility is because of the mild surfactant system, the calming ingredient bisabolol, and the absence of potentially irritating ingredients.

Sensitive skin: an overview

Sensitive skin is a condition of subjective cutaneous hyper-reactivity to environmental factors. Subjects experiencing this condition report exaggerated reactions when their skin is in contact with cosmetics, soaps and sun screens, and they often report worsening after exposure to dry and cold climate. Although no sign of irritation is commonly detected, itching, burning, stinging and a tight sensation are constantly present. Generally substances that are not commonly considered irritants are involved in this abnormal response.Sensitive skin and subjective irritation are widespread but still far from being completely defined and understood. A correlation between sensitive skin and constitutional anomalies and/or other triggering factors such as occupational skin diseases or chronic exposure to irritants has been hypothesized. Recent findings suggest that higher sensitivity can be due to different mechanisms. Hyper-reactors may have a thinner stratum corneum with a reduced corneocyte area causing a higher transcutaneous penetration of water-soluble chemicals. Alterations in vanilloid receptors and changes in neuronal transmission have been described. Monitoring skin parameters such as barrier function, proclivity to irritation, corneocyte size and sensorial transmission can also be useful to identify regional differences in skin sensitivity.

The itchy scalp--scratching for an explanation

Scalp pruritus is a common complaint that is considered a diagnostically and therapeutically challenging situation. Scalp skin has a unique neural structure that contains densely innervated hair follicles and dermal vasculature. In spite of the recent advances in our understanding of itch pathophysiology, scalp itching has not been studied as yet. In this review, we summarize the current knowledge on the neurobiology of scalp and hair follicles as well as itch mediators and provide a putative mechanism for scalp itch with special emphasis on neuroanatomy and pathophysiology.

Sensitive skin and rosacea: nosologic framework

Flushing due to rosacea may be mistaken for sensitive skin, which can manifest as abnormal sensations during fairly acute reactions to a variety of triggers, many of which are shared by rosacea and sensitive skin. Nevertheless, the two conditions are clearly different. Rosacea is a vascular disease, worsens gradually over time, manifests as flares triggered chiefly by systemic factors, is largely confined to the facial and/or ocular regions, and responds to specific treatments. Sensitive skin, in contrast, is an epidermal cosmetic problem that runs a variable course, with diffuse skin involvement and flares triggered mainly by contact factors. The flares respond to specific cosmetics and are usually worsened by treatments for rosacea.

[Sensitive skin and rosacea: nosologic framework]

Flushing due to rosacea may be confused with sensitive skin because it is characterized by slightly acute reactions to varied factors with the perception of abnormal sensations and often common triggering factors. Nevertheless, these are clearly two different phenomena. On the one hand, rosacea is a vascular disease, with progressive worsening and eruptions set off by systemic factors, with a facial and/or ocular topography that respond to specific treatments. On the other hand, sensitive skin corresponds to an epidermal, cosmetic problem, with variable progression, whose eruptions are instead set off by contact factors and have a ubiquitous topography. Eruptions are improved by specific cosmetics and usually worsened by rosacea treatments.