Photosensitive atopic dermatitis - a neglected subset: Clinical, laboratory, histological and photobiological workup

Continuum of light sensitivity in atopic dermatitis: A retrospective analysis of 139 cases in Scotland

BACKGROUND

Previous reports have characterized photosensitivity in atopic dermatitis (AD), but with differences in terminology and criteria.

OBJECTIVE

This study aims to assess outcomes in 139 patients with AD referred for photodiagnostic testing and to establish diagnostic criteria for photosensitivity in AD.

METHODS

Clinical and photodiagnostic data were reviewed, categorizing photosensitivity into photoexacerbated AD, photosensitive AD, and chronic actinic dermatitis.

RESULTS

Of the patient cohort, the mean age was 42.6 ± 16.7 years, and 61.9% were men. In total, 51.1% of the patients with photoexacerbated AD had normal monochromator phototesting, and 7.9% of the patients with photosensitive AD displayed slight-to-moderate ultraviolet (UV)-A sensitivity (≥30% of normal minimal erythema dose [MED]) and mostly normal or slightly reduced UV-B MEDs (≥80% of normal MED). Conversely, 41% of the patients had chronic actinic dermatitis, and 93% of this group demonstrated significant UV-B sensitivity, with very low UV-B MEDs (<80% of normal MED) and/or very low UV-A MEDs (<30% of normal MED). No significant differences in sex, age, or skin phototype were observed between the groups. Serial phototesting revealed changes in photosensitivity status over time in 8 patients.

LIMITATIONS

A small sample size and retrospective design.

CONCLUSIONS

This study highlights the heterogeneity of photosensitivity patterns in patients with AD and the importance of follow-up assessments due to potential shifts in disease spectrum over time.

Chronic actinic dermatitis: A 5-year clinical analysis of 488 patients in China

BACKGROUND/PURPOSE

Chronic actinic dermatitis (CAD) is a spectrum of diseases with chronic photosensitivity occurring mostly among middle-aged and older men. We seek to explore the characteristics and pathogenesis of CAD among the Chinese population.

METHODS

The medical records of 488 CAD cases diagnosed by phototesting at Huashan Hospital, Fudan University from January 2014 to December 2018 were analyzed retrospectively.

RESULTS

Among the 488 patients, 344 were male and 144 were female. 84.8% of the cases were over 40 years old at the age of onset, while the remaining with an early age of onset had a prevalence of atopic history of 21.6%. Up to 45.0% of the patients reported excessive sun exposure and outdoor activities before the initiation of symptoms. The typical skin lesions were erythema, papules and plaques laid predominantly in sun-exposed areas. 42.8% of the cases showed sensitivity to UVB only, 20.7% were both sensitive to UVA and UVB, and 18.2% had UVA sensitivity only. The most predominant photoallergens were chlorpromazine (80.1%), thimerosal (17.2%), potassium dichromate (12.7%), etc. The most prevalent patch test allergens were potassium dichromate (24.4%), thimerosal (20.5%), formaldehyde (16.8%), etc. CONCLUSIONS: CAD was more commonly seen in males over 40 years old. The action spectrum of Chinese patients is primarily in the UVB range. Exposure to excessive sunlight or contact allergens and photoallergens are important risk factors. Photobiology tests are essential in detecting photosensitivity and recognizing potential photosensitizers. Early avoidance of confirmed photoallergens and sun exposure may prevent photosensitive reactions from progressing into persistent photosensitivity.

Photosensitivity is an important cause of refractory facial erythema in atopic dermatitis: A retrospective study of 82 Chinese patients

BACKGROUND

Ultraviolet radiation can aggravate facial erythema in atopic dermatitis (AD) patients.

OBJECTIVE

To investigate the photobiological testing results of Chinese AD patients with refractory facial erythema.

METHODS

We conducted a retrospective analysis of 82 AD patients with refractory facial erythema who visited our department during 2004-2021. All of them completed phototesting and photopatch testing.

RESULTS

82 patients were enrolled in the study, and 53 (64.6%) were between 18 and 30 years old. 51.2% (42/82) had positive phototesting results and were considered photosensitive AD (PhAD) patients. One-third of them were both allergic to ultraviolet A and ultraviolet B. 65.9% (54/82) suffered from photoallergic contact dermatitis. Chlorpromazine (50.7%), potassium dichromate (13.2%), and thimerosal (11.8%) were the top three common photoallergens. Overall, 86.3% of AD patients with refractory facial erythema had direct photoallergy or photocontact allergy. PhAD patients had fewer allergic comorbidities than the other group (p = .007). More non-PhAD patients (55.0%) suffered from AD at 2-14 years old (p = .015).

CONCLUSIONS

Photosensitivity contributes a lot to the facial lesions of AD patients, especially in their 20s. 86.3% of these patients had direct photoallergy or photocontact allergy. Therefore, AD patients with facial erythema should undergo phototesting and photopatch testing routinely.

Clinicophotobiological Characterization of Photoaggravated Atopic Dermatitis

Importance

Photoaggravated atopic dermatitis (PAD) is estimated to affect 1.4% to 16% of patients with AD but remains poorly characterized with limited published data.

Objective

To provide detailed clinical and photobiological characterization of PAD.

Design, Setting, and Participants

This case series study used cross-sectional data collected from 120 consecutive patients diagnosed with PAD from January 2015 to October 2019 at a tertiary center referral unit for photobiology.

Main Outcomes and Measures

Routinely collected standardized clinical and photobiological data were analyzed using descriptive statistics, and regression analysis explored associations between demographic and clinical data.

Results

Of 869 patients who underwent photoinvestigation, 120 (14%) were diagnosed with PAD (69 female [58%]; median age, 45 [IQR, 31-61] years; range, 5-83 years; skin phototypes [SPTs] I-VI). Of these patients, 104 (87%) were adults. All patients had a history of AD, and most (62 of 104 [60%]) presented with sunlight-provoked or photodistributed eczema; median age at photosensitivity onset was 37 years (range, 1-72 years). Past-year Dermatology Life Quality Index score was greater than 10 for 80 of 103 adults (78%), and 82 of 119 (69%) had vitamin D (25-hydroxyvitamin D) level insufficiency or deficiency (<20 ng/mL; to convert ng/mL to nmol/L, multiply by 2.496). Broadband UV radiation provocation test results were positive for 112 patients (93%). In 28 patients (23%) with abnormal monochromator phototest findings, sensitivity occurred to UV-A, UV-B, and/or visible light, and UV-A of 350 ± 10 nm was the most prevalent wavelength. Photopatch test reactions were positive for 18 patients (15%). Patients with SPTs V to VI (31 [26%]) vs SPTs I to IV (89 [74%]) were younger at photosensitivity onset (median age, 24 years [IQR, 15-37 years] vs 40 years [IQR, 25-55 years]; P = .003), were more likely to be female (23 [74%] vs 46 [52%]; P = .03), and had a lower vitamin D status and a higher frequency of abnormal monochromator phototest findings.

Conclusions and Relevance

In this case series study, PAD affected patients with different ages and SPTs and was associated with substantially impaired quality of life. The findings suggest that confirming PAD through phototesting may provide better personalized care for patients through identification of provoking wavelengths, relevant photocontact allergies, and appropriate photoprotection advice.

Dupilumab Demonstrates Rapid and Consistent Improvement in Extent and Signs of Atopic Dermatitis Across All Anatomical Regions in Pediatric Patients 6 Years of Age and Older

INTRODUCTION

In phase III trials in adolescents and children with atopic dermatitis (AD), dupilumab significantly decreased global disease severity. However, the effects of dupilumab on the extent and signs of AD across different anatomical regions were not reported. Here we characterize the efficacy of dupilumab in improving the extent and signs of AD across four different anatomical regions in children and adolescents.

METHODS

A post hoc subset analysis was performed using data from two randomized, double-blind, placebo-controlled, international multicenter, phase III trials of dupilumab therapy in adolescents aged ≥ 12 to < 18 years with moderate-to-severe AD and children aged ≥ 6 to < 12 years with severe AD. Endpoints included mean percentage change in Eczema Area and Severity Index (EASI) signs (erythema, edema/papulation, excoriation, lichenification) and extent of AD (measured by percentage of body surface area [% BSA] involvement) from baseline to week 16 across four anatomical regions (head and neck, trunk, upper extremities, lower extremities).

RESULTS

Dupilumab improved both the extent and severity of AD signs across the four anatomical regions. Improvements were shown to be similar across the four anatomical regions for % BSA involvement and for reduction in EASI signs. Improvements in all signs were seen early, within the first 4 weeks of treatment, and were sustained through week 16, across all regions.

CONCLUSIONS

In pediatric patients 6 years of age and older, treatment with dupilumab resulted in rapid and consistent improvement in the extent and signs of AD across all anatomical regions. CLINICALTRIALS.

GOV IDENTIFIERS

LIBERTY AD ADOL (NCT03054428) and LIBERTY AD PEDS (NCT03345914). Does dupilumab provide improvement in atopic dermatitis across all anatomical regions in children and adolescents? (MP4 48,385 kb).

Clinical and biological impact of the exposome on the skin

The skin exposome is defined as the totality of environmental exposures over the life course that can induce or modify various skin conditions. Here, we review the impact on the skin of solar exposure, air pollution, hormones, nutrition and psychological factors. Photoageing, photocarcinogenesis and pigmentary changes are well-established consequences of chronic exposure of the skin to solar radiation. Exposure to traffic-related air pollution contributes to skin ageing. Particulate matter and nitrogen dioxide cause skin pigmentation/lentigines, while ozone causes wrinkles and has an impact on atopic eczema. Human skin is a major target of hormones, and they exhibit a wide range of biological activities on the skin. Hormones decline with advancing age influencing skin ageing. Nutrition has an impact on numerous biochemical processes, including oxidation, inflammation and glycation, which may result in clinical effects, including modification of the course of skin ageing and photoageing. Stress and lack of sleep are known to contribute to a pro-inflammatory state, which, in turn, affects the integrity of extracellular matrix proteins, in particular collagen. Hormone dysregulation, malnutrition and stress may contribute to inflammatory skin disorders, such as atopic dermatitis, psoriasis, acne and rosacea.

The Role of Photoprotection in Optimizing the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease with an estimated prevalence of 10-15% in children and 2-10% in adults. Clinically, there is notable phenotypic variability driven by a complex interaction between genetics, immune function, and the environment. Impairment of the skin barrier plays a significant role in the pathogenesis of AD. The apparent beneficial effect of sunlight in patients with atopic eczema is questioned due to its capacity to disrupt the skin barrier and generate free radicals that can damage proteins, lipids, and DNA. The sum of the external factors that an individual is exposed to throughout their lifetime is termed the exposome. Environmental factors such as sun exposure, temperature, and humidity contribute to both AD flares and regional prevalence variation. Literature on photoprotection in atopic dermatitis is very scarce. The use of adequate sunscreens in atopic dermatitis can ensure the level of photoprotection required to prevent skin photoaging and skin cancer and to mitigate skin barrier dysfunction, decrease inflammation, and neutralize facial redness. Herein we discuss and review the role of UV radiation and the exposome in the etiology of AD, as well as the role of adequate photoprotection.

Clinical and pathological findings of chronic actinic dermatitis

BACKGROUND

Chronic actinic dermatitis (CAD) is a recurrent photosensitive disease occurs predominantly in elderly men on sun-exposed areas, which seriously affect the patient's life quality. The etiology of CAD remains unknown.

METHODS

Sixty-six CAD patients, 66 atopic dermatitis (AD) patients, and 46 healthy people were enrolled into this study. Patient-level data were obtained from the electronic medical record and laboratory databases. We also obtained 29 tissue samples including 16 lichenoid lesions, 7 minimal erythematous dose (MED) analysis induced lesions, and 6 normal skin samples. Histopathologic and immunohistochemical analysis were performed.

RESULTS

In the clinical characteristics, albumin was lower and uric acid was higher significantly in patients diagnosed as CAD. The infection rate of CAD patient after skin biopsy was considerably high (23.3%). The serum allergen test was prone to be negative in CAD patients. Lymphocytes were the dominate infiltrating cells in early and late CAD lesions, while more CD4+, CD8+, CD69+, and CD103 + cells were found in the late lesions. There is no difference in CD4+/CD8 + ratio and CD69+/CD103 + ratio among groups. More mast cells were observed in the early-stage lesions, and more dendritic cell was observed in the late-stage lesions.

CONCLUSIONS

CAD patients have certain oxidative stress and are prone to be infected after skin biopsy. Serum allergen detection is of little significance for CAD diagnosis. Mast cells may be involved in the early process of CAD, while dendritic cells and tissue-resident memory T cell (TRM) may be related to the chronic process of the disease.

Ultraviolet A rush hardening for chronic actinic dermatitis: Pilot treatment outcomes

Chronic actinic dermatitis (CAD) is a common debilitating photodermatosis. Patients often have to completely avoid outdoor activities, which severely impacts their quality of life. Phototherapy is effective for CAD and seems to increase patients' tolerance towards sunlight and consequently decrease the extent of disease. Unfortunately, the slower onset and time-consuming nature of phototherapy limits the clinical application. Considering the effectiveness and time-saving nature of ultraviolet (UV)-A rush hardening in solar urticaria, we performed a pilot study to determine whether UV-A rush hardening is effective in CAD. Six patients with CAD were exposed to multiple sessions of UV-A for 4-5 days at 1-h intervals/day. Subsequently, maintenance UV-A exposure was performed at 1-2-week intervals. Phototesting at baseline showed that three patients were sensitive to both UV-A and -B, and the other three patients only showed UV-A sensitivity. All of the patients responded well to UV-A rush hardening and four (67%) maintained a good remission status after 1 year. The results of this pilot study suggest that UV-A rush hardening phototherapy is effective and well tolerated in the treatment of CAD, while future larger prospective studies using objective scores of disease activity and quality of life are needed.

Human health in relation to exposure to solar ultraviolet radiation under changing stratospheric ozone and climate

The Montreal Protocol has limited increases in the UV-B (280-315 nm) radiation reaching the Earth's surface as a result of depletion of stratospheric ozone. Nevertheless, the incidence of skin cancers continues to increase in most light-skinned populations, probably due mainly to risky sun exposure behaviour. In locations with strong sun protection programs of long duration, incidence is now reducing in younger age groups. Changes in the epidemiology of UV-induced eye diseases are less clear, due to a lack of data. Exposure to UV radiation plays a role in the development of cataracts, pterygium and possibly age-related macular degeneration; these are major causes of visual impairment world-wide. Photodermatoses and phototoxic reactions to drugs are not uncommon; management of the latter includes recognition of the risks by the prescribing physician. Exposure to UV radiation has benefits for health through the production of vitamin D in the skin and modulation of immune function. The latter has benefits for skin diseases such as psoriasis and possibly for systemic autoimmune diseases such as multiple sclerosis. The health risks of sun exposure can be mitigated through appropriate sun protection, such as clothing with both good UV-blocking characteristics and adequate skin coverage, sunglasses, shade, and sunscreen. New sunscreen preparations provide protection against a broader spectrum of solar radiation, but it is not clear that this has benefits for health. Gaps in knowledge make it difficult to derive evidence-based sun protection advice that balances the risks and benefits of sun exposure.

Exposure to Ultraviolet Radiation in the Modulation of Human Diseases

This review focuses primarily on the beneficial effects for human health of exposure to ultraviolet radiation (UVR). UVR stimulates anti-inflammatory and immunosuppressive pathways in skin that modulate psoriasis, atopic dermatitis, and vitiligo; suppresses cutaneous lesions of graft-versus-host disease; and regulates some infection and vaccination outcomes. While polymorphic light eruption and the cutaneous photosensitivity of systemic lupus erythematosus are triggered by UVR, polymorphic light eruption also frequently benefits from UVR-induced immunomodulation. For systemic diseases such as multiple sclerosis, type 1 diabetes, asthma, schizophrenia, autism, and cardiovascular disease, any positive consequences of UVR exposure are more speculative, but could occur through the actions of UVR-induced regulatory cells and mediators, including 1,25-dihydroxy vitamin D₃, interleukin-10, and nitric oxide. Reduced UVR exposure is a risk factor for the development of several inflammatory, allergic, and autoimmune conditions, including diseases initiated in early life. This suggests that UVR-induced molecules can regulate cell maturation in developing organs.