The histopathology of vitiligo in brown skin

Vitiligo is characterized histopathologically by loss of melanocytes in the basal layer which eventually results in the absence of melanin in the epidermis. Only few studies have been conducted in brown skin, and most of our knowledge on the pathologic changes in the epidermis and dermis are based on studies done involving an assortment of races and skin phototypes. The role of cellular immunity in vitiligo pathogenesis has been pointed out by the use of immunohistochemistry to identify the cellular components of vitiligo lesions. Common clinical and histological differential diagnosis of vitiligo in brown skin includes diseases presenting with hypo- and depigmentation. These include idiopathic guttate hypomelanosis, pityriasis alba, postinflammatory pigmentary alteration, hypopigmented mycosis fungoides (MF), and tuberculoid leprosy. More studies on the histopathology of vitiligo in brown skin should be conducted to identify prominent features and further highlight the cellular immune elements which potentially drive the unique inflammatory responses

Rosacea

Rosacea is a common chronic inflammatory skin condition which is commonly observed in middle-aged women. The 2018 revised classification by the National Rosacea Society emphasizes the need for a phenotype-driven approach in the diagnosis of rosacea. Persistent centrofacial redness and phymas are now considered as independent diagnostic criteria for rosacea. Papules, pustules, facial telangiectasias and ocular findings are considered as major features. More recently, dermatologists have been more keen on differentiating cases of acne and rosacea because the treatment and prognosis are different. A gamut of systemic and topical medications is available and the efficacy and side effects have been evaluated in many clinical trials. Interestingly, new articles on the characteristics of rosacea in pigmented skin have been published, since the skin condition has always been considered as more common among Caucasians and fair-skinned individuals. Acquired forms of rosacea and various disease associations, especially the metabolic syndrome, have been recently discussed in published observational studies. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022

The histopathology of melasma in brown skin

Racial variations exist in the distribution of melanin and melanosomes in the epidermis; however, no racial differences are observed in melanocyte density and concentration. Melanosomes in pigmented skin are distributed in the entire epidermis unlike in fair skin where only few melanosomes are found in the basal and malpighian layers. Studies on melasma in brown skin consistently show increased epidermal melanocytes and melanin in all the layers of the epidermis accompanied by solar elastosis and mild perivascular infiltrate. The presence of melanophages is a variable observation and raises the question whether there is indeed a “dermal” type of melasma. Important clinical differential diagnoses include ochronosis, dermal melanocytosis, ashy dermatosis (AD), erythema dyschromicum perstans (EDP), lichen planus pigmentosus (LPP), Riehl’s melanosis, and minocycline pigmentation, which are conditions mostly observed in Fitzpatrick skin type IV brown skin. A skin biopsy is indispensable when melasma presents with unusual clinical features or has become recalcitrant to treatment. It may be useful to establish the nature and pathology of facial hyperpigmentation and determine changes in the underlying dermis which may provide clues to the diagnosis

Latrogenic Dyschromia: A Preliminary Report on 6 Cases on The Clinical, Dermoscopy and Histopathology Findings

In the Philippines and other Asian countries, “bleaching creams” containing various concentrations and mixtures of hydroquinone, steroids and retinoids are often used without regulation. With immediate improvement, most patients lack follow-up and continue to self-medicate without knowing the complications of long- term use. Iatrogenic dyschromia refers to skin color alteration induced by medical treatment or inadvertently by physicians. To the best of our knowledge, the clinical and histopathologic characteristics have not been fully elucidated yet. We have identified 6 females with Fitzpatrick skin phototype IV with mottled pigmentation on the forehead, nose and cheeks initially diagnosed as exogenous ochronosis. Dermoscopy revealed intervening white and light brown areas, visible follicular openings and extensive network of vessels. Histopathology showed basal cell layer hyperpigmentation of the epidermis. The dermis revealed telangiectasias, solar elastosis and focal degeneration of collagen fibers. Masson’s trichrome revealed thinning of collagen bundles. Melan-A stain revealed melanocytopenia. The dermatologist should be able to recognize iatrogenic dyschromias as they differ from melasma and ochronosis in clinical, histopathologic and dermoscopy findings. Continuous application of skin lightening agents without sun protection is most likely the major predisposing factor in the development of this condition. A larger study is warranted to fully define this condition

Review update on topical therapy for psoriasis

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Purpose of Review: Studies show frequent usage but low adherence rates and poor satisfaction from topical therapy for psoriasis. These were attributed to low efficacy, inconvenience of application, and poor cosmetic quality for different body parts. Recent Findings: Multicenter surveys on patients suggest a two-way holistic approach, where patients convey what bothers them most and doctors explain how products address specific concerns. New rapid response targeted topical agents, in cosmetically acceptable preparations, applied less often, are undergoing efficacy and safety studies, ideally on large populations up to 1 year or more. Until available, this review addresses gaps in knowledge on how to maximize effects of emollients, used alone, with physiologic lipids, or as base for active topical therapy. Summary: Updates—on how psoriasis skin becomes itchy, red, dry, thick, and scaly from inflammation and barrier defects—explain clinical responses to the physical, chemical, and functional properties of psoriasis topical therapies

Climate change, human migration, and skin disease: is there a link?

Climate change, exemplified by higher average global temperatures resulting in more frequent extreme weather events, has the potential to significantly impact human migration patterns and health. The consequences of environmental catastrophes further destabilize regions with pre-existing states of conflict due to social, political, and/or economic unrest. Migrants may carry diseases from their place of origin to their destinations and once there may be susceptible to diseases in which they had not been previously exposed to. Skin diseases are among the most commonly observed health conditions observed in migrant populations. To improve awareness among dermatologists of the burden of skin diseases among migrants, the group searched the English language scientific literature to identify articles linking climate change, migration, and skin disease. Skin diseases associated with human migration fall into three major categories: (i) communicable diseases, (ii) noncommunicable diseases, and (iii) environmentally mediated diseases. Adopting comprehensive global strategies to improve the health of migrants requires urgent attention