Synopsis
Describe skin lesions precisely using reproducible primary and secondary morphology, recognise changes caused by evolution or manipulation, and communicate findings without relying on colour alone.
- Primary lesions include macules, patches, papules, plaques, nodules, vesicles, bullae, pustules, wheals and cysts; measure rather than estimating their size.
- Secondary change includes scale, crust, erosion, ulceration, excoriation, fissure, atrophy, lichenification and scar, and may obscure the initiating lesion.
- Describe colour with morphology and palpation: erythema may appear bright red, violaceous, dusky, brown or grey depending on pigmentation and inflammation depth.
- A vesicle contains clear fluid and is usually under 1 cm; a bulla is larger, while a pustule contains visibly purulent material that is not necessarily infectious.
- For Primary and secondary lesion morphology, describe what is seen before assigning a diagnosis, and record site, extent, symptoms, duration and change over time.
- A technically adequate result in Primary and secondary lesion morphology can still be misleading when the wrong lesion, site, preparation or clinical question was selected.
Key red flags
A rapidly spreading painful eruption, dusky skin, blistering, mucosal erosion or systemic illness requires urgent assessment rather than prolonged descriptive refinement.
Erosion is epidermal loss and usually heals without scar; ulceration extends into dermis and demands a cause, depth and edge description.
Investigation priorities
Define the dominant primary lesion and surface change.
Management branches
The patient is stable and the result will alter diagnosis, referral or follow-up.
- Define the question for Primary and secondary lesion morphology, explain the process and obtain valid consent before exposing, touching, photographing or sampling skin.
- Choose representative anatomy, optimise lighting or specimen technique, and document site, morphology, symptoms and relevant previous treatment.
- Interpret the result beside the full clinical pattern, communicate uncertainty and arrange ownership of results and safety-netting.