How to Pass the FRACP Written Examination. Jonathan Gleadle

      Iannacone MR. Effects of sunscreen on skin cancer and photoaging. Photodermatol Photoimmunol Photomed 2014; 30: 55–61. https://onlinelibrary.wiley.com/doi/full/10.1111/phpp.12109

       11. Answer: B

      The skin is made up of three layers, the most superficial layer is the epidermis and the layer below is the dermis, followed by the third layer of subcutaneous tissue. The epidermis is further divided into five layers in areas of thick skin, such as the palms and soles: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum. While in areas of thinner skin, the epidermis has four layers, without the stratum lucidum.

      The dermis is further divided into two layers, the papillary dermis (the upper layer) and the reticular dermis (the lower layer) which contains the vasculature. The skin is highly vascularised; there is an extensive network of larger blood vessels and capillaries that extend from regional branches of the systemic circulation to local sites throughout subcutaneous tissue and dermis, respectively. Therefore, it is likely that the excision has traversed the reticular dermis to cause profuse bleeding. In addition, there is an extensive lymphatic network that runs alongside many of the skin’s blood vessels, particularly those attached to the venous end of the capillary networks.

       12. Answer: D

      Stevens Johnson Syndrome (SJS)/Toxic Epidermal Necrolysis (TEN) are severe skin disorders characterised by mucosal involvement, extensive skin necrosis and epidermal detachment. SJS is classified by <10% body surface area (BSA) involvement, Overlap syndrome 10–20% BSA and TEN >30% BSA. It is usually caused by antibiotics, anticonvulsants, allopurinol, and anti‐inflammatory medications commenced 2–3 weeks prior to presentation.

      Supportive care has been shown to be the most important treatment for patients with SJS/TEN. It should consist of managing skin wounds, haemodynamic stability, electrolyte balance, maintenance of airway and pain control. Guidelines suggest that covering the denuded skin can improve skin barrier function, reduce water and protein loss, limit microbial colonisation and promote reepithelialisation.

      Systemic steroids were considered to be the primary treatment option for many years, however recent studies have reported a lack of efficacy and in some cases worsened mortality from increased risk of infection, delayed healing and prolonged hospitalisation. The use of IVIG has had controversial conflicting results. A recent meta‐analysis showed no difference in mortality when comparing patients who received IVIG compared to those who received supportive care. Although some studies have showed that higher dosages of IVIG may lower mortality.

There have also been several case reports with positive results for TNFα inhibitors such as Etanercept in the treatment of SJS/TEN. There is one published case series of 10 patients who responded well with complete reepithelialisation, however it will need further studies to validate these results. Cyclosporine is an immunosuppressive agent inhibiting CD8+ T cells. One study found a significant and beneficial effect of cyclosporine when compared to supportive care. Although it seems to be a promising treatment, it is contraindicated in patients with severe renal dysfunction, infection, malignancy, and sepsis. Patients with SJS/TEN often have secondary infection, organ dysfunction, and other comorbidities, which limits its use.