Lesson 01.pdf

Introduction to Dermatology Lesson 01  Intended Learning Outcomes, After completion of this lesson the student will be able to, 1. Define the word dermatology 2. Explain the importance of the study of dermatology 3. Identify the basic terms used in dermatology field Introduction to D...

Introduction to Dermatology Lesson 01  Intended Learning Outcomes, After completion of this lesson the student will be able to, 1. Define the word dermatology 2. Explain the importance of the study of dermatology 3. Identify the basic terms used in dermatology field Introduction to Dermatology What is dermatology? Dermatology is the study of both normal and abnormal skin and associated structures such as hair, nails, and oral and genital mucous membranes. Why is dermatology important? I. The skin is the human body’s largest organ, so if that isn’t enough to take good care of it. II. Skin diseases are very common, affecting up to a third of the population at any one time. III. Skin diseases have serious impacts on life. They can cause physical damage, mental discomfort, and social and occupational restrictions. IV. Dermatology can help individuals to overcome acne, examine skin spots, receive skin cancer screening, treat eczema or psoriasis etc. General terms used in Dermatology Pruritus -Itching Lesion -An area of altered skin Rash-An eruption Naevus -A localized malformation of tissue structures Pigmented melanocytic naevus (mole) (Picture Source: D@nderm)  Comedone -Comedones are small, flesh-colored, white, or dark bumps that give skin a rough texture. They are found at the opening of skin pores. A solid core can often be seen in the middle of the small bump. Comedones are called open or closed based on whether the surface is disrupted (open) or intact (closed). Open comedones are blackheads and closed comedones are whiteheads. Open comedones (left) and closed comedones (right) in acne  Distribution (the pattern of spread of lesions) Generalized - All over the body Widespread - Extensive Localized - Restricted to one area of skin only Flexural - Body folds i.e. groin, neck, behind ears, popliteal and antecubital fossa Extensor -Knees, elbows, shins Pressure areas -Sacrum, buttocks, ankles, heels Dermatome - An area of skin supplied by a single spinal nerve Photosensitive - Affects sun-exposed areas such as face, neck and back of hands The pattern or shape of grouped lesions Discrete Individual lesions separated from each other Confluent Lesions merging together Linear In a line Target Concentric rings (like a dartboard) Annular Like a circle or ring Discoid / A coin-shaped/round lesion  Colour Erythema - Redness (due to inflammation and vasodilatation) which blanches on pressure Hypo- pigmentation- Area(s) of paler skin Eg-: a superficial fungus infection  De-pigmentation: White skin due to absence of melanin Examples: Vitiligo - loss of skin melanocytes Hyper-pigmentation - Darker skin which may be due to various causes Examples : post- inflammatory, melasma, naevi The structure of a lesion Macule -A flat area of altered colour Example : Freckles Patch -Larger flat area of altered colour or texture Papule - Solid raised lesion < 0.5cm in diameter Example : Xanthomata  Nodule -Solid raised lesion >0.5cm in diameter with a deeper component Plaque -Palpable scaling raised lesion >0.5cm in diameter Pustule -Pus-containing lesion