Necrobiosis lipoidica (NL) is a rare skin disorder that causes significant distress due to its unsightly appearance and propensity to ulcerate. There is a poor understanding of the underlying pathophysiology which ranges from microvascular angiopathy to collagen disruption. Current treatment options, including corticosteroids, immunomodulators and phototherapy, have potentially serious side effects and limited effectiveness. Evidence is sparse and heavily varied, with no well-evidenced guidelines or management approaches that is agreed upon. Properly applied compression therapy has strong evidence in the management of lower limb wounds, and the same physiological effects may have a role in NL therapy. This review seeks to consolidate the current understanding of the underlying pathogenesis and explore current and potential treatment options, including compression therapy, with a focus on the proposed mechanisms of action of therapy for NL.

Pyoderma gangrenosum (PG) is a neutrophilic dermatosis that is uncommon and can sometimes be associated with systemic diseases. The pathophysiology underlying this condition is poorly understood, although recent advances suggest that local cutaneous abnormalities and functionally abnormal neutrophils may trigger ongoing innate and adaptive immune system activity. PG remains a difficult condition to diagnose, mainly because it was previously seen as a diagnosis of exclusion, although newer diagnostic criteria have been proposed in order to overcome this. Furthermore, many patients do not respond to conventional therapy for PG once diagnosed, and experience persistence or worsening of their condition over time. The advent of immune targeted therapies, however, may represent a new treatment option for these patients. This review focuses on the clinical features and diagnosis of PG, as well as providing an update in our understanding of the pathophysiology and treatment options available for this debilitating condition.

Alopecia areata (AA) is a T cell-mediated autoimmune disease that has an estimated lifetime prevalence of 2.1%. Although clinically heterogenous, the typical presentation is of discrete, well-demarcated patches of non-scarring hair loss. In severe AA, complete loss of scalp hair (alopecia totalis, AT) or all hair (alopecia universalis, AU) may occur. There is considerable variation in how AA is treated by dermatologists. Recent insights into the aetiopathogenesis of AA have led to the emergence of several novel treatment strategies, including Janus kinase inhibitors and biologics. This review provides a contemporary evidence-based summary of AA, including clinical features, severity assessment, disease pathogenesis and current and emerging treatment strategies.

There are dramatic disparities in the life expectancy, health and healthcare access between Indigenous and non-Indigenous Australians. The burden of chronic disease is significantly elevated and contributed to by multiple socioeconomic determinants of health. Cutaneous disease, both infectious and inflammatory, have major contributions to the risk of developing chronic disease in later life and contributing to barriers to education, employment and healthcare.

Atopic dermatitis (AD) is a common, burdensome inflammatory skin disease worldwide; however, a paucity of literature exists reviewing the prevalence in Indigenous Australians. Typical therapies of AD are time-consuming and burdensome and can be an additional barrier to treatment compliance. However, multiple novel targeted therapeutics now exist for the effective and safe management of AD which are demonstrated to reduce the risk of cutaneous infections. Effective early and prioritised access to such therapies in the setting of moderate to severe AD may represent a potential intervention, with downstream benefits in the development of chronic disease. Nevertheless, there are multiple outstanding questions regarding the safety of such therapies in the setting of endemic infections such as scabies and strongyloidiasis which require attention, as well as the practicalities for such therapies to be administered in rural and remote communities.

Overall, the appreciation of the role of cutaneous inflammatory and infectious disease as a contributor to health disparities in Indigenous populations is sorely needed. Discussion regarding the risk-benefit and cost-efficacy of targeted therapeutics in moderate to severe AD and consideration of prioritised access to Indigenous patients in need should be undertaken as part of a wider health prevention strategy with community input.

Hidradenitis suppurativa (HS) is a chronic autoinflammatory disease characterised by recurrent painful nodules, abscesses, sinus tracts and scars at apocrine gland-bearing sites. Treatment is universally challenging and sufferers may live with chronic and recurrent draining wounds. This review provides an up-to-date, evidence-based summary of HS, including clinical features, severity assessment, disease pathogenesis and current and emerging therapeutic approaches.

The nails, in combination with skin, glands and hair, comprise the integumentary system. Abnormalities in the colour, shape and clinical appearance of nails can be indicative of pathophysiological disorders, habit-tics such as bitten nails, poor grooming, nutritional deficits and cosmetic practices. Discolouration and changes in nail appearance are common reasons for referral of individuals to dermatologists. This paper presents a mélange of common nail disorders with a clinical focus on those that present with discolouration.

Pathergy reaction is the phenomenon of formation of non-healing skin lesions or ulcers following minor injuries. Although conceptually similar to the isomorphic reaction (Koebnerisation), these are two separate phenomena that should be distinguishable to treating clinicians. The underlying pathomechanisms of pathergy are not yet fully understood and subsequently therapy is lacking. Recent advances in the understanding of wound healing through keratinocyte and fibroblast cross-talk and mesenchymal stem cell (MSC) may hopefully foster the development of novel targeted therapies for pathergy-associated wounds and diseases in the near future.