Week 3 Rash (Moodle Version) (1).pdf

DIAGNOSTIC APPROACH TO UNDIFFERENTIATED RASH IN A YOUNG ADULT CMS 150 LEARNING OUTCOMES Utilize a systematic approach to the diagnosis of rash Differentiate between primary and secondary lesions Describe rashes using medical terminology Apply the ABCDE criteria for detecting melanoma...

DIAGNOSTIC APPROACH TO UNDIFFERENTIATED RASH IN A YOUNG ADULT CMS 150 LEARNING OUTCOMES Utilize a systematic approach to the diagnosis of rash Differentiate between primary and secondary lesions Describe rashes using medical terminology Apply the ABCDE criteria for detecting melanoma Differentiate between global reaction patterns Understand the roles of clinical and laboratory aids in the diagnosis of rash CONSTRUCTING A DIFFERENTIAL DIAGNOSIS FOR A RASH IN A YOUNG ADULT What is a rash? An inflammatory skin eruption Differential diagnosis of a rash is primarily based on morphology of the lesion. 1. First identify the primary lesion, this is the lesion that is the typical element of the eruption. 2. Determine the global reaction pattern. 3. Distribution of the lesions. (diffuse, isolated, localized, regional, universal?) Primary lesion: initial lesion that has not been altered by trauma or manipulation, and has not regressed Secondary lesion: develops as the disease evolves or as the patient damages the lesion i.e. rubbing, scratching, infections. Primary Lesions Bulla A circumscribed, elevated lesion that measures ≥ 1 cm and contains serous or hemorrhagic fluid (i.e., a large blister) Macule A circumscribed, nonpalpable discolouration of the skin that measures 0.3 cm. Pustule A lesion that contains pus; may be follicular (centered around a hair follicle) or nonfollicular. Vesicle A circumscribed, elevated lesion that measures