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Roxburgh’s skin diseases common: Part 2

(BQ) Continued part 1, part 2 of the document Roxburgh’s skin diseases common has contents: Acne, rosacea and similar disorders, wound healing and ulcers, malignant disease of the skin, skin problems in infancy and old age, metabolic disorders and reticulohistiocytic proliferative disorders, management of skin disease, and other contents. Invite you to refer. | CHAPTER Acne rosacea and similar disorders 10 Acne 149 Rosacea 162 Perioral dermatitis 168 Summary 169 The disorders described in this chapter are common inflammatory characterized clinically by papules and occur on the face pre-eminently. These features do not imply a common aetiopathogenesis. Acne Acne is one of the commonest skin disorders - if not the commonest. It has been estimated that 70 per cent of the population have some clinically evident acne at some stage during adolescence DEFINITION Acne acne vulgaris is a disorder in which hair follicles develop obstructing horny plugs comedones as a result of which inflammation later develops around the obstructed follicles causing tissue destruction and scar formation. CLINICAL FEATURES The lesions The earliest feature of the disorder is an increased rate of sebum secretion making the skin look greasy seborrhoea . Blackheads or comedones usually accompany the greasiness. They often occur over the sides of the nose and the forehead but can occur anywhere Fig. 10.1 . Comedones are follicular plugs composed 149 Acne rosacea and similar disorders Figure 10.1 Multiple comedones and seborrhoea in acne. Figure 10.2 Multiple comedones in acne. Note the blackened tips from melanin. of follicular debris and compacted sebum. They have pigmented tips from the melanin pigment deposited by the follicular epithelium at this level Fig. 10.2 . Accompanying the visible comedones are numerous invisible comedones many of which do not have pigmented tips. Inflamed reddened papules develop from blocked follicles. These are often quite tender to the touch and may be set quite deep within the skin Fig. 10.3 . Sometimes they develop pus at their tips pustules but these may also arise independently. In a few patients some of the papules become quite large and persist for long periods - they are then referred to as nodules. In severely affected patients the nodules liquefy centrally so that fluctuant cysts are formed. In reality the .