[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Clinical exam](https://durgical.com/en/clinical-exam/) › [Skin, head and neck](https://durgical.com/en/clinical-exam/#a-head_neck) › Skin examination: primary and secondary lesions

[Clinical exam](https://durgical.com/en/clinical-exam/) · [Skin, head and neck](https://durgical.com/en/clinical-exam/#a-head_neck)

# Skin examination: primary and secondary lesions

- Exam technique

How the skin is looked at and felt, and how its lesions are named so that any colleague understands what you saw.

Updated 2026-11-01

**See it in 3D:** [Skin](https://durgical.com/en/anatomy/skin/)

## Key points

- The usual cut-off between macule/patch, papule/plaque and vesicle/bulla is 1 cm (some texts use 0.5 cm).
- Flat and non-palpable = macule or patch; raised and solid = papule, plaque or nodule; raised with fluid = vesicle, bulla or pustule.
- The urticarial wheal is transient: each lesion lasts under 24 hours.
- An erosion heals without a scar; an ulcer, which reaches the dermis, scars.
- Diascopy separates erythema (blanches) from petechia or purpura (does not blanch).

## What it is

The skin exam combines inspection in good light with palpation of the whole skin surface, hair, nails and visible mucosa. Its core is describing each lesion in a shared vocabulary: the primary lesion type (what appears first) and secondary changes (what evolution, scratching or infection leave behind). A precise description guides the differential diagnosis before any test and lets the lesion be followed over time.

## Landmark anatomy

- Epidermis: the surface layer; its changes produce scale, crust and colour change through the melanocytes of the basal layer.
- Dermis: holds vessels, nerves and appendages; dermal oedema makes the wheal, dermal inflammation makes papules and plaques.
- Hypodermis (subcutis): the fat where deep nodules such as erythema nodosum sit.
- Fluid-filled lesions form by splitting within the epidermis or between epidermis and dermis; the level changes the look (flaccid or tense blister).

## Technique, step by step

- Explain the exam, ask permission and ensure privacy; use daylight or bright white light and uncover one region at a time.
- Inspect in order, head to toe: scalp, face, trunk, limbs, skin folds, palms, soles, web spaces, nails and mucosa.
- Note the overall colour: pallor, cyanosis, jaundice, erythema and hyperpigmentation (in dark skin, check conjunctivae, gums and palms).
- Feel temperature with the back of the hand; texture, moisture and thickness with the fingertips.
- Check turgor by gently pinching the skin below the clavicle or on the forearm and watching how fast it returns.
- For each lesion, define the primary type, size measured with a ruler, colour, shape, border and surface.
- Palpate the lesion: flat or raised, solid or fluid-filled, consistency, tenderness and whether it is fixed.
- Press with a glass slide or a finger (diascopy): if it does not blanch, blood is outside the vessels (petechia, purpura).
- Describe the distribution (localised, generalised, symmetric, sun-exposed, flexural) and arrangement (linear, annular, grouped, dermatomal).
- Record it all in descriptive language and, when possible, a photo with a scale for comparison at follow-up.

## Primary lesions: the basic vocabulary (the 1 cm cut-off is the most used; some texts use 0.5 cm)

| Lesion | Definition | Example |
| --- | --- | --- |
| Macule | Flat, non-palpable colour change under 1 cm | Freckle, petechia |
| Patch | Flat, non-palpable colour change over 1 cm | Vitiligo, café-au-lait spot |
| Papule | Solid, palpable elevation under 1 cm | Wart, insect bite |
| Plaque | Solid elevation with a broad surface, over 1 cm | Psoriasis |
| Nodule | Solid, deeper lesion (dermis or subcutis), over 1 cm | Lipoma, erythema nodosum |
| Vesicle | Elevation filled with clear fluid, under 1 cm | Chickenpox, herpes simplex |
| Bulla | Elevation filled with clear fluid, over 1 cm | Second-degree burn, pemphigoid |
| Pustule | Elevation containing pus (not always infected) | Acne, folliculitis |
| Wheal | Transient oedematous elevation, lasts under 24 hours | Urticaria |
| Cyst | Cavity with fluid or semisolid content, fluctuant to touch | Epidermoid cyst |

## Abnormal findings

- Secondary lesions: scale (shedding stratum corneum), crust (dried serum or blood), erosion (partial epidermal loss, heals without a scar) and ulcer (reaches the dermis, scars).
- Other secondary lesions: fissure (linear crack), excoriation (scratch injury), lichenification (skin thickened by chronic rubbing), atrophy and scar.
- Non-blanching petechiae and purpura, especially with fever, point to a bleeding disorder or severe infection and are reported at once.
- Grouped vesicles on a dermatome suggest herpes zoster; wheals that move within hours suggest urticaria.
- Nursing angle: assess pressure-injury risk over bony prominences (sacrum, heels) and report any non-blanching redness.

## Common errors

- Using diagnoses instead of descriptions ('looks like eczema') rather than naming the primary lesion.
- Examining in poor light or only the area the patient points to; many important lesions sit in hidden places (scalp, soles, between toes).
- Forgetting that erythema and pallor look different in dark skin; compare with nearby normal skin and with mucosa.
- Not measuring: 'large' or 'small' cannot be compared at follow-up.

## Memory aid

First 'what it is' (type), then 'what it looks like' (size, colour, border), last 'where it is' (distribution): describe before you name.

## Test yourself

Think of the answer, then tap the question to see it.

## What is a raised, solid, 3 cm lesion with a flat scaly surface on the elbow called?

A plaque (solid raised lesion over 1 cm); with silvery scale on the elbow, psoriasis is the classic example.

## What separates an erosion from an ulcer?

An erosion loses only part of the epidermis and heals without a scar; an ulcer reaches at least the dermis and scars.

## What is diascopy for?

Pressing on the lesion: erythema blanches because the blood is inside vessels; petechiae and purpura do not, because the blood has left the vessels.

## How long does each urticarial wheal typically last?

Under 24 hours; one lesion fades while another appears somewhere else.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/clinical-exam/skin-examination-primary-and-secondary-lesions/)

## See it in 3D

The structures of Durgical's 3D anatomy where it is found.

- [Skin](https://durgical.com/en/anatomy/skin/)

## Related

- [The ABCDE of pigmented lesions](https://durgical.com/en/clinical-exam/the-abcde-of-pigmented-lesions/)
- [Pallor, cyanosis and jaundice](https://durgical.com/en/clinical-exam/pallor-cyanosis-and-jaundice/)
- [Digital clubbing and nail signs](https://durgical.com/en/clinical-exam/digital-clubbing-and-nail-signs/)
- [Edema: pitting, grading and distribution](https://durgical.com/en/clinical-exam/edema-pitting-grading-and-distribution/)
- [Hydration status: signs of dehydration](https://durgical.com/en/clinical-exam/hydration-status-signs-of-dehydration/)
- [Nursing assessment: head-to-toe and focused assessment](https://durgical.com/en/clinical-exam/nursing-assessment-head-to-toe-and-focused-assessment/)

## Related conditions

- [Psoriasis](https://durgical.com/en/conditions/psoriasis/)
- [Atopic dermatitis](https://durgical.com/en/conditions/atopic-dermatitis/)
- [Contact dermatitis (irritant and allergic)](https://durgical.com/en/conditions/contact-dermatitis/)
- [Urticaria and angioedema](https://durgical.com/en/conditions/urticaria-and-angioedema/)
- [Impetigo](https://durgical.com/en/conditions/impetigo/)
- [Varicella (chickenpox)](https://durgical.com/en/conditions/varicella/)
- [Herpes zoster (shingles)](https://durgical.com/en/conditions/herpes-zoster/)
- [Scabies](https://durgical.com/en/conditions/scabies/)
- [Acne vulgaris](https://durgical.com/en/conditions/acne-vulgaris/)

[← All of the clinical exam](https://durgical.com/en/clinical-exam/)

Educational content on the clinical exam; it is learned and practised under supervision. It does not replace assessment by a health professional and is not for self-diagnosis.

Sources: [Terminology in dermatology](https://dermnetnz.org/topics/terminology) (DermNet, 2026); [Description of Skin Lesions - Dermatology - Merck Manual Professional Edition](https://www.merckmanuals.com/professional/dermatologic-disorders/approach-to-the-dermatologic-patient/description-of-skin-lesions) (Merck Manuals, 2026); [21.1 Structure and Functions of the Skin - Clinical Nursing Skills | OpenStax](https://openstax.org/books/clinical-nursing-skills/pages/21-1-structure-and-functions-of-the-skin) (OpenStax, 2024).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/clinical-exam/skin-examination-primary-and-secondary-lesions/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/clinical-exam/skin-examination-primary-and-secondary-lesions/