Congenital ichthyoses (CI) are rare, inherited skin disorders characterized by hyperkeratosis, scaling and fissuring that significantly impair patients' quality of life. Treatment options are limited, with systemic retinoids reserved for severe cases owing to their adverse effect profile. This open-label, single-arm, maximal-use trial investigated the systemic exposure and safety of a topically administered isotretinoin ointment (TMB-001 0.05%) in patients with moderate-to-severe CI. Thirty-four patients aged ≥6 years applied TMB-001 0.05% under maximal-use conditions (twice daily to 75%-90% of the body surface area) for 14 days, with continued application for another 10 weeks. Exposure levels for TMB-001 0.05% and its metabolites were < 1% of those observed after single oral administration of 80 mg isotretinoin to healthy adults. A majority of patients had local safety or tolerability issues, most of which were mild. Overall, the treatment was well tolerated with no evidence of systemic toxicity.

Isotretinoin, a potent retinoid, is highly effective in the treatment of severe acne vulgaris. Its nearly 60-year history began with the Swiss pharmaceutical company La Roche in the 1960s, where it was initially studied for potential benefits in cancer treatment. This article delineates the historic trajectory of isotretinoin from early clinical trials in the 1970s and 1980s, highlighting its efficacy and safety profile, leading to FDA approval in 1982. The review also addresses contemporary concerns such as the drug's teratogenicity and potential link to depression, providing an overview of regulatory measures and mixed research findings on mental health and sexual dysfunction. Additionally, the current status of isotretinoin in other medical areas, including its exploration as a chemotherapy adjunct, is examined.

The skin microbiome consists of the microorganisms populating the human skin. Cutibacterium acnes (C. acnes, formerly named Propionibacterium acnes) is recognized as a key factor in acne development, regulating inflammatory and immune pathways. Dysbiosis has been described as the imbalance in skin microbiome homeostasis and may play a role in acne pathogenesis. Microbial interference has been shown to be a contributor to healthy skin homeostasis and staphylococcal strains may exclude acne-associated C. acnes phylotypes. In this review we present an update on the skin microbiome in acne and discuss how current acne treatments such as benzoyl peroxide, orally administered isotretinoin, and antibiotics may affect the skin microbiome homeostasis. We highlight the collateral damage of acne antibiotics on the skin microbiome, including the risk of antimicrobial resistance and the dysregulation of the microbiome equilibrium that may occur even with short-term antibiotic courses. Consequently, the interest is shifting towards new non-antibiotic pharmacological acne treatments. Orally administered spironolactone is an emerging off-label treatment for adult female patients and topical peroxisome proliferator-activated receptor gamma (PPARγ) modulation is being studied for patients with acne. The potential application of topical or oral probiotics, bacteriotherapy, and phage therapy for acne are further promising areas of future research.

Acne vulgaris is a prevalent dermatological condition worldwide but is especially challenging to treat in individuals with skin of colour (SOC). Corresponding to Fitzpatrick skin phototypes III-VI, people of African, Asian, Middle Eastern and Hispanic ethnicity are considered to have SOC. With the additional risk of postinflammatory hyperpigmentation (PIH) as a consequence of inflammatory acne or its respective treatment, managing acne in this population holds significant importance. PIH adversely impacts self-esteem and quality of life and, thus, is usually the patient's priority of treatment. Available acne treatments are similar for all skin types. However, some are more beneficial for individuals with SOC, in particular by targeting both active acne lesions and PIH. The acne treatment literature was searched for topical and systemic treatments that were specifically studied in the SOC population. These treatments included topical agents, such as retinoids and azelaic acid, in addition to topical antibiotics and benzoyl peroxide. Newer formulations and combined regimens reported effective in reducing lesions are less likely to induce PIH and may treat pre-existing PIH. Moisturiser use, titrating doses and patient education are strategies to minimize irritation and improve adherence. In addition, systemic therapies, including oral antibiotics, isotretinoin, oral contraceptives and spironolactone, are efficacious for refractory acne or more severe cases but specific studies in SOC are lacking. Chemical peels may improve acne and target PIH directly. Overall, based on limited evidence, topical and systemic therapies are well tolerated in the SOC population but efficacy should be balanced with the risk of adverse effects. This narrative review aims to highlight formulations and combination therapies that are effective and safe for treating acne and PIH in patients with SOC.

Darier's disease (also known as keratosis follicularis or dyskeratosis follicularis) is an autosomal dominant inherited disorder which manifests as hyperkeratotic greasy papules in the first or second decade of life. Aside from symptom management and behavioral modifications to avoid triggers, there are currently no validated treatments for Darier's disease (DD). However, a variety of treatments have been proposed in the literature including retinoids, steroids, vitamin D analogs, photodynamic therapy, and surgical excision. The purpose of this review article is to identify therapeutic options for treating DD and to outline the evidence underlying these interventions. A search was conducted in Medline for English language articles from inception to July 4, 2020. Our search identified a total of 474 nonduplicate studies, which were screened by title and abstract. Of these, 155 full text articles were screened against inclusion/exclusion criteria, and 113 studies were included in our review. We identified Grade B evidence for the following treatments of DD: oral acitretin, oral isotretinoin, systemic Vitamin A, topical tretinoin, topical isotretinoin, topical adapalene gel, topical 5-flououracil, topical calciptriol and tacalcitol (with sunscreen), grenz ray radiation, and x-ray radiation. All other evidence for treatments of DD consisted of case reports or case series, which is considered grade C evidence. Considering the quality and quantity of evidence, clinicians may consider initiating a trial of select topical or oral retinoids first in patients with localized or generalized DD, respectively.