Itchy Rash D. Erichsen MD

Case 2 siblings, 16 and 13 y. o present with rash Trunk > extremities, face spared Itch started immediately after swimming Rash after 1 day ROS negative

Case Pmhx: none Meds: benadryl prn. only No previous episodes No other sick contacts

Case presentation Nomenclature Differential Case discussion

Nomenclature Lesion –A lesion is any single area of altered skin. It may be solitary or multiple. Rash –A rash is a widespread eruption of lesions. The rules –A description and picture of an example of a dermatological term will be provided –You have one guess –Each participant has 2 lifelines You may ask anyone in the room once excluding myself and the chief resident You may ask for a clue once

Descriptive term? Round (coin- shaped) lesions. Also known as discoid.

Nummular lesion Round (coin- shaped) lesions. Also known as discoid.

Descriptive term? A straight shape to a lesion often occurs for some external reason such as scratching. Also striate.

Linear lesion A straight shape to a lesion often occurs for some external reason such as scratching. Also striate.

Descriptive term? Concentric rings like a dartboard. Also known as iris lesion.

Target lesion Concentric rings like a dartboard. Also known as iris lesion.

Descriptive term? Lesions grouped in a circle.

Annular lesion Lesions grouped in a circle.

Dermatological term? An area of color change less than 1.5 cm diameter. The surface is smooth.

Macule A macule is an area of color change less than 1.5 cm diameter. The surface is smooth.

Dermatological term? A large area of color change, with smooth surface.

Patch A patch is a large area of color change, with smooth surface.

Dermatological term? Small palpable lesions. Less than 0.5 cm diameter, although some authors allow up to 1.5 cm. Raised above the skin surface, and may be solitary or multiple.

Papule Small palpable lesions. Less than 0.5 cm diameter, although some authors allow up to 1.5 cm. Raised above the skin surface, and may be solitary or multiple.

Dermatological term? An enlargement of a papule in three dimensions (height, width, length). It is a solid lesion.

Nodule An enlargement of a papule in three dimensions (height, width, length). It is a solid lesion.

Dermatological term? A purulent vesicle. It is filled with neutrophils, and may be white, or yellow. Not all are infected.

Pustule A purulent vesicle. It is filled with neutrophils, and may be white, or yellow. Not all are infected.

Dermatological term? A large fluid-filled blister. It may be a single compartment or multiloculated.

Bulla(e) A large fluid-filled blister. It may be a single compartment or multiloculated.

Dermatological term? A localised collection of pus.

Abscess A localised collection of pus.

Dermatological term? An oedematous papule or plaque caused by swelling in the dermis. Often indicates urticaria.

Weal An oedematous papule or plaque caused by swelling in the dermis. Often indicates urticaria.

Dermatological term? Change in skin caused by chronic rubbing, which results in palpably thickened skin with increased skin markings.

Lichenification Change in skin caused by chronic rubbing, which results in palpably thickened skin with increased skin markings.

Dermatological term? Occurs when plasma exudes through an eroded epidermis. It is rough on the surface and is yellow or brown in colour.

Crust Occurs when plasma exudes through an eroded epidermis. It is rough on the surface and is yellow or brown in colour.

Dermatological term? A scratch mark. It may be linear or a picked scratch (prurigo). May occur in the absence of a primary dermatosis.

Excoriation A scratch mark. It may be linear or a picked scratch (prurigo). May occur in the absence of a primary dermatosis.

Differential Skeeter syndrome Insect bites Scabies

Skeeter Syndrome IgE mediated allergic skin reaction to mosquito saliva. Young children, immuno-compromised and visitors at increased risk. Difficult to distinguish from cellulitis. –Develops within hours Benign –Topical hydrocortisone –Bacitracin –Benadryl

Insect bites Can cause similar local reactions Diagnosis of exclusion Treatment similar to Skeeter Syndrome

Scabies