Week 3: Rash Flashcards

Question

Ruling out Melanoma and Dysplastic Nevi – The ABCDE’s

Answer 1

1. Asymmetry 2. Irregular Borders 3. Variegated Colour 4. Diameter – a lesion larger than 6 mm is at higher risk for malignancy 5. Evolution/Enlargement – a lesion that changes over time is at higher risk for malignancy

Answer 2

Magnification with hand lens Hand lens (7 x magnification) Binocular microscope (5 x to 40x magnification) Oblique lighting: Used to view degrees of elevation or depression in a lesion. Done in a darkened room. Subdued lighting: Used to enhance the contrast between circumscribed hypopigmented or hyperpigmented lesions and normal skin. Wood lamp (365 nm ultraviolet long-wave light, “black” light): Can pick up fluorescent pigments and subtle colour differences of melanin pigmentation. Causes some superficial lesions to fluoresce. Vitiligo presents as amelanotic Tinea capitis and tinea versicolor can sometimes be visualized with wood lamp but not likely tinea corporis, as many references would suggest – depends on the species of fungus Porphyrias Erythrasma Some bacterial infections (pseudomonas) Deep (reticular dermal) lesions typically do not fluoresce under a Wood lamp Typically used by dermatologists, not necessary in naturopathic medical practice Diascopy Firmly pressing a microscopic slide or glass spatula over a skin lesion. The examiner determined whether the red colour of a macule of papule is due to capillary dilatation (erythema) or due to extravasation of blood (purpura) that does not blanch. Dermoscopy (also called epiluminescence microscopy) A hand lens with built-in lighting and a magnification of 10x to 30x is called a dermatoscope and allows for inspection of deeper layers of the epidermis and beyond. Helpful to distinguish between a benign and malignant lesion. These tools are typically used by dermatologists and not necessary in a naturopathic medical practice

Answer 3

Patch testing Used to confirm a diagnosis of allergic contact sensitization and identify the agent that caused the allergic reaction. Substances to be tested are applied to the skin in shallow cups (Finn chambers), taped onto the skin and left in place for 24 – 48 hours. Contact hypersensitivity will show as a papular vesicular reaction that will develop within 48 to 72 hours when the test is read. Prick testing Used to determine type I allergies A drop of a solution containing a small amount of the allergen is placed on the skin and the skin is pierced through this drop with a needle. A positive result would be a wheal appearing within 20 minutes. Caution – the patient needs to be under constant supervision due to possibility of anaphylaxis. Skin scraping Dermatophyte/KOH Collection Microscopic examination for mycelia should be made of the roofs of vesicles or of scales or in the hair in dermatophytosis. The tissue is cleared with 10 to 30% KOH and warmed gently. Hyphae and spores can then be viewed. Microbiology (Culture and Sensitivity) and Specimen Handling Biopsy *Note most of these clinical tests are performed by allergists or dermatologist, some ND’s offer prick testing and skin scraping, but a patient can be referred out for further evaluation. Biopsy Different tools can be used for different types of lesions Punch biopsy: Useful in the work-up of cutaneous neoplasms, pigmented lesions, inflammatory lesions and chronic skin disorders. 3 to 4 mm punch, a small tubular knife cuts through the epidermis, dermis and subcutaneous tissue by rotating the tool. Excisional biopsy (wide local excision) Surgical removal of a tumour and some normal tissue around it.

Answer 4

(more charts on this in slides)

Week 3: Rash Flashcards

(33 cards)