Common Allergens Identified Based on Patch Test Results in Patients with Suspected Contact Dermatitis of the Scalp

Engineered Exosomes Biopotentiated Hydrogel Promote Hair Follicle Growth via Reprogramming the Perifollicular Microenvironment

Androgenetic alopecia (AGA) is a highly prevalent condition in contemporary society. The conventional treatment of minoxidil tincture is hindered by issues such as skin irritation caused by ethanol, non-specific accumulation in hair follicles, and short retention due to its liquid form. Herein, we have developed a novel minoxidil-incorporated engineered exosomes biopotentiated hydrogel (Gel@MNs) that has the capability to modulate the perifollicular microenvironment for the treatment of AGA. Leveraging the exceptional skin penetration abilities of flexible liposomes and the targeting properties of exosomes, the encapsulated minoxidil can be effectively delivered to the hair follicles. In comparison to free minoxidil, Gel@MNs demonstrated accelerated hair regeneration in an AGA mouse model without causing significant skin irritation. This was evidenced by an increase in both the number and size of hair follicles within the dermal layer, enhanced capillary formation surrounding the follicles, and the regulation of the transition of hair follicle cells from the telogen phase to the anagen growth phase. Therefore, this safe and microenvironment-modifying hybrid exosome-embedded hydrogel shows promising potential for clinical treatment of AGA.

Allergic Contact Dermatitis to Topical Preparations Containing Minoxidil: A Systematic Review and Individual Participant Data Meta-Analysis

Topical minoxidil is generally well tolerated, yet there have been a few reports of allergic contact dermatitis (ACD) confirmed through patch testing. This systematic review and individual participant data meta-analysis sought to elucidate the primary allergens in patients exhibiting ACD in response to topical minoxidil formulations and to ascertain the appropriate testing concentrations and vehicles of minoxidil itself. A comprehensive search was conducted across the PubMed, Scopus, and Embase databases utilizing the keywords "minoxidil" and "contact dermatitis," or "contact allergy," or "contact eczema." Studies documenting ACD in patients using topical minoxidil confirmed by patch testing were deemed eligible. Our analysis included 46 studies encompassing 99 patients with patch-test-confirmed ACD to minoxidil-based topical treatments. The majority of these patients (93.9%) were exposed to minoxidil without additional active components. Minoxidil itself was identified as the primary allergen in 74.7% of the patients, with propylene glycol being the next most common allergen at 17.1%. Other allergens identified included estradiol, butylene glycol, methylchloroisothiazolinone/methylisothiazolinone, canrenone, and latanoprost. The most effective concentration was found to be 2% minoxidil in propylene glycol, which yielded a 100% positivity rate. The findings indicate that minoxidil is the predominant allergen in ACD reactions to its topical formulations, followed by propylene glycol. For the accurate diagnosis of ACD related to minoxidil, patch testing with 2% minoxidil in propylene glycol is recommended, as are separate tests for propylene glycol and other potential allergenic ingredients.

Nickel release from hairdressing tools in the United States

BACKGROUND

Hairdressers have a high prevalence of contact dermatitis, especially to nickel. The presence of nickel in hairdressing tools has been evaluated in the European Union, where the government limits nickel release levels from objects.

OBJECTIVES

The aim of this study is to qualitatively investigate nickel release in hairdresser tools in both rural and urban United States, a country without nickel release legislation.

METHODS

Hairdressers and individuals with hairdressing tools were invited to participate. Metallic parts of each tool were tested with dimethylglyoxime (DMG), which detects nickel release. Data on tool cost were recorded.

RESULTS

A total of 89 tools from 9 salons and 2 over-the-counter sets were tested. Twenty-four (27%) tested positive: trimmers (100%), curling irons (100%), clippers (50%), hair clips (36%), texturizing shears (26%), and trimming shears (4%). Nickel was detected in both salon and over-the-counter tools, and rural and urban salons. Nickel-releasing tools were cheaper than DMG-negative tools of the same type.

CONCLUSIONS

Our findings help explain the high prevalence of contact dermatitis among hairdressers, alert clinicians to consider occult occupational nickel when assessing patients with allergic contact dermatitis, reinforces the importance of using barrier protection including gloves when handling hairdressing tools including at home, and augments impetus for more legislation regulating common allergens.

Potential for Allergic Contact Dermatitis in Popular Hair Care Practices and Ingredients

The incidence of allergic contact dermatitis (ACD) due to personal care products is rising in parallel with increasing product availability and consumer interest. Hair products specifically represent a significant source of potential allergens, including preservatives, surfactants, emulsifiers, fragrances, adhesives, and dyes. ACD due to hair care products can present as dermatitis in the distinctive "rinse-off" distribution, involving the neck, eyelids, and lateral face in addition to the scalp. Herein, the authors review ingredients in hair care products that can cause ACD and practical tips for allergen identification.

Allergic Contact Dermatitis of the Scalp Associated With Scalp Applied Products: A Systematic Review of Topical Allergens

ABSTRACT

Hair products are commonly used to maintain hair health or cosmesis. Products applied to the scalp and hair contain multiple active and inactive ingredients that can potentially cause irritant and/or allergic contact dermatitis. The objectives of this study were to identify and to discuss the most common allergens in scalp and hair applied products causing scalp allergic contact dermatitis (ACD). A PubMed search identified 99 studies, with 3185 patients and 31 categories of scalp products. Hair products reportedly associated with scalp ACD were hair dyes (41%), shampoos (28%), and conditioners (22%). The most commonly reported patch test-positive allergens were p-phenylenediamine (23%), nickel (15%), fragrance mix (13%), balsam of Peru (10%), cocamidopropyl betaine/3-dimethylaminopropylamine (7%), and methylchloroisothiazolinone/methylisothiazolinone (6%). Common symptoms and signs include eczematous lesions, pruritus, and a burning sensation. Medical practitioners should be aware of causative agents to provide appropriate patient education, counseling, and/or treatment.

Compatibility of Different Formulations in TrichoConceptTM Vehicles for Hair Treatments

The wide variety of potential pathogeneses for alopecia and the wide variety of active pharmaceutical ingredients (APIs) to treat and manage those pathogeneses highlight the importance of the development of stable and effective topical treatments. Topical options for alopecia on the market remain limited and oral products may result in unwanted systemic adverse effects. This study is meant to fill the gap by determining compatibility in terms of beyond-use date (BUD) of APIs with theoretical or demonstrated benefits for topical use for alopecia. The compatibility of seven formulations was tested: F1 = clobetasol 0.05% in TrichoWashTM; F2 = ketoconazole 2% in TrichoWashTM; F3 = spironolactone 1% in TrichoWashTM; F4 = latanoprost 0.1% in TrichoCreamTM; F5 = pyridoxine HCl 0.5%, vitamin A acetate 1%, and vitamin E succinate 12.1 IU in TrichoCondTM; F6 = Caffeine 2%, menthol 1%, and pyridoxine HCl 0.5% in TrichoWashTM; F7 = Latanoprost 0.1%, minoxidil 5%, and finasteride 0.25% in TrichoSolTM. All formulations presented a BUD of 6 months, except for F4 and F7, which showed compatibility for 3 months. This validates the compatibility of the APIs with the TrichotechTM vehicles, and that they are highly convenient for compounding pharmacies.

Clinical and trichoscopic features in various forms of scalp psoriasis

BACKGROUND

Scalp psoriasis is often undiagnosed or inadequately treated. The patient himself underestimates the seriousness of this hair disease and consults too late to a dermatologist.

OBJECTIVES

The aim of our study was to create a correlation between the clinical patterns and trichoscopy of scalp psoriasis such in a way to help the clinician to make the diagnosis and select the appropriate therapy.

MATERIAL AND METHODS

We gathered all patients affected of scalp psoriasis afferent to Outpatient's hair consultation of the Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, from January 2012 to December 2018. All patients were evaluated through clinical, trichoscopic examination and a skin biopsy only in doubtful cases. We quantified the severity of the disease with several objective and subjective parameters every 4 months, up to 1 year. We recorded therapies, outcome data and quality of life.

RESULTS

We collected 156 patients affected by scalp psoriasis, identifying seven clinical patterns with specific trichoscopical correlation. In the order of frequency, the clinical patterns were as follows: plaque psoriasis (with a prevalence of erythema, silver-white scales and twisted red loops vessels and red dots); thin scales (with silvery-white scales, simple red lines and signet red ring vessels); sebopsoriasis (with greasy scales, erythema with red dots, globules and twisted and bushy red loops at high magnification); psoriatic cap (with silver-white scales, erythema and polymorphic vascular pattern); pityriasis amiantacea (with yellowish adherent scales, erythema and simple red loops capillaries); cicatricial psoriatic alopecia (with erythema associated with yellowish, silver-white scales with twisted and bushy red loops capillaries) and pustular psoriasis (with 'flower shape' pustular lesions, erythema simple red loops capillaries).

CONCLUSIONS

The description of different clinical patterns of scalp psoriasis and its trichoscopical correlations may help the clinician to make the diagnosis also in atypical presentations and to prescribe an adequate therapeutic regimen.

Environmental Causes of Dermatitis

Environmental, or exogenous, dermatitis is comprised of irritant and allergic contact dermatitis, which account for 80% and 20% of cases of contact dermatitis, respectively. Contact dermatitis is extremely common, and failure to diagnose this entity may result in overlooking a potentially curable driver of disease. In this review, we describe how clinical features, such as morphology or history, can assist in distinguishing exogenous from endogenous causes of dermatitis, and allergic from irritant contact dermatitis. Additionally, we provide an overview of common contact allergens and how dermatitis distribution can suggest possible culprit allergens. Patch testing is needed to confirm contact allergy.

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.

Analysis of Epicutaneous Patch Test Results in Patients with Contact Dermatitis

Background:

Allergic contact dermatitis (ACD) is a delayed type of hypersensitivity from contact with a specific allergen to which the patients has developed a specific sensitivity. The aim of the study was to evaluate the results of epicutaneous patch testing with standard series of contact allergen in patients suspected to have ACD.

Methods:

355 cases of ACD were included in the study. Test substances were applied on the upper part of the patient’s back, on clinically uninvolved and untreated skin. All patients were free from therapy with oral antihistamines, steroids and immunosuppressants. The patch test was removed and reaction were evaluated after 48 h and 72 h. Grading of negative (-) to positive (+ to ++++) patch test was done according to the International Contact Dermatitis Research Group. Statistical data analysis was performed by using χ²–test.

Results:

Of the 355 cases, 146 patients were male (41.1%) and 209 were female (58.9%). The youngest patients in the study was 16 years of age and the oldest was 67 years of age. The commonest age group affected was 41-50 years. Hands were the most common site of involvement. The occupational character of skin lesions was find in 75 (21.1%). The most common positive reactions were recorded to nickel sulphate 99 (27.8%), cobalt chloride 46 (12.9%), thimerosal 31 (8.7%), colophony 23 (6.5%), carba mix 21 (5.9%), potassium dichromate 20 (5.6%), acid chromici 19 (5.3%), fragrance mix 18 (5%), balsam of Peru 13 (3.7%), formaldehyde 9 (2.5%), and other allergens 26 (7.3%). Females were significantly more likely to show a positive response to two or more allergens (p<0.05). There was no statistically significant impact of age, occupation and duration of disease on results of patch testing (p>0.05).

Conclusions:

Our results indicate that nickel sulphate, cobalt chloride and thimerosal are the most common allergens responsible for induction of ACD. These findings are crucial in the treatment, long term management, an education of patients with ACD.