CCFP priority topic 82 of 105
Rash on the CCFP exam
8 key features, the mistakes that cost marks, and a practice question.
Checked by a Canadian family physician, MD, CCFP. Updated October 20, 2026.
What the exam tests
Key features
The CFPC’s 8 key features for Rash. Each one below has how the exam asks it, the common mistakes and the approach.
Practice question
Try one before you read
A real case from the bank, in the new short-menu format. Answer it first. Then read the key features.
Key feature 1 of 8
History and skin exam
When a rash first appears, ask the key questions and look closely; go wider if still unsure.
CFPC skill Clinical reasoning, selectivityPhase History, physical
On the exam
A young adult has fever and new dark spots on the legs, after camping and two doses of ibuprofen. Expect a short menu (pick several from a list) of history and exam steps.
Pick the questions and checks that matter now.
Common mistakes
Chasing the camping trip or the ibuprofen, or reaching for a magnifier. The bedside check that matters is whether the spots fade when you press on them.
Approach
- Check vital signs before you study the rash. A sick patient changes the whole plan.
- Ask when it started, where, how fast it spread, and whether it itches or hurts.
- Ask about fever, new drugs, contacts with a rash, travel, bites and vaccines.
- Press on red or dark spots. Spots that do not fade under pressure (non-blanching), with fever, are an emergency.
- If the cause is still unclear, look at all the skin: scalp, nails, palms, soles, mouth, eyes and genitals.
- On darker skin, redness can look purple or brown. Check paler areas such as the palms, soles and inner eyelids.
- Then examine other systems as the clues point: joints, lymph nodes, liver and spleen.
Key feature 2 of 8
Know the patterns
Use the look and layout of a rash to reach a likely diagnosis.
CFPC skill Clinical reasoningPhase DiagnosisSources Choosing Wisely Canada
On the exam
An older adult has red, swollen lower legs on both sides and no fever. Expect one best answer for the diagnosis.
Pick the most likely diagnosis.
Common mistakes
Calling it cellulitis and giving antibiotics. Redness of both lower legs is often a mimic, such as stasis dermatitis (skin change from poor vein return).
Approach
- Name the pattern first: what it looks like, where it is, and how it is laid out (table below).
- Red, swollen lower legs on both sides: think of stasis dermatitis. Do not give antibiotics by reflex.
- A ring with a scaly edge suggests tinea. Confirm it with a skin scraping before you treat.
- Check the setting: age, season, new drugs, and contacts with the same rash.
- If the pattern does not fit, say so. Go back to the history and the full exam.
| Pattern | Think of | Supporting clue |
|---|---|---|
| Red, swollen lower legs on both sides | Stasis dermatitis | Leg swelling or varicose veins, no fever |
| Grouped blisters in one band on one side | Shingles | Pain or tingling before the rash |
| Ring with a scaly edge and a clearer centre | Tinea | Scraping shows fungus |
| Itchy raised weals that move around | Hives | Each weal fades and leaves no mark |
| Thick scaly plaques on elbows, knees and scalp | Psoriasis | Pitted nails |
Key feature 3 of 8
Describe it right
Describe skin lesions in standard words so notes and referrals are clear.
CFPC skill CommunicationPhase Physical, follow-up
On the exam
A stem describes flat purple spots that do not fade with pressure. Expect one best answer for the right term.
Pick the correct descriptive term.
Common mistakes
Writing “red rash” for spots that do not fade, or calling a flat spot a papule. Vague words hide purpura and delay care.
Approach
- Describe in order: type, colour, shape, layout and site. The table gives the types.
- Shape: round, a ring (annular), a target, or a line.
- Layout: grouped, scattered, or in one nerve band (dermatome).
- Site: one side or both, skin folds, sun-exposed skin, palms and soles.
- Note the surface: scale, crust, weeping or an ulcer.
- Use the same words at each visit and in referrals, so change is easy to track.
| Term | Means | Example |
|---|---|---|
| Macule, patch | Flat colour change; a patch is larger | Freckle, vitiligo |
| Papule, plaque | Raised and solid; a plaque is broad and flat-topped | Psoriasis |
| Vesicle, bulla | Fluid-filled blister; a bulla is larger | Chickenpox, bullous pemphigoid |
| Pustule | Raised and filled with pus | Acne, folliculitis |
| Petechiae, purpura | Blood in the skin that does not fade with pressure; petechiae are pinpoint | Meningococcal sepsis, low platelets |
Key feature 4 of 8
Sick patient with a rash
When a rash comes with a sick patient, spot the deadly causes and act at once.
CFPC skill Clinical reasoning, selectivityPhase Hypothesis generation, diagnosis, treatment, referral
On the exam
Fever of 39.4 °C, blood pressure 94/56 mm Hg and spreading dark spots that do not fade. Expect a short menu (pick several from a list) of first steps.
Pick what you do in the first minutes.
Common mistakes
A head CT, a lumbar puncture, a skin biopsy or oral Lyme cover before the antibiotic. Each delays the step that saves life. An antihistamine for a “drug rash” is wrong too.
Approach
- Fever, low blood pressure and spots that do not fade: treat as meningococcal sepsis until proven otherwise.
- Give intravenous (IV) antibiotics at once. Do not wait for a scan, a lumbar puncture or a biopsy.
- Draw blood cultures first only if that causes no delay.
- Start IV fluids for shock. Arrange transfer to emergency or intensive care.
- Know the other killers and their clues (table below). Each needs hospital care today.
- A drug rash or a vasculitis does not explain fever with shock. Do not let either idea slow treatment.
| Condition | Clues | Do now |
|---|---|---|
| Meningococcal sepsis | Fever, low blood pressure, dark spots that do not fade and spread fast | IV antibiotics now, fluids, transfer |
| Necrotizing fasciitis | Pain worse than the redness looks, fast spread, sick patient | Urgent surgical review, IV antibiotics |
| Toxic shock syndrome | Fever, low blood pressure, sunburn-like red rash; tampon or wound | Remove the source, fluids, IV antibiotics |
| Stevens-Johnson syndrome | New drug, painful skin, blisters, sores in the mouth or eyes | Stop the drug, hospital care |
Key feature 5 of 8
Rash that will not settle
When a rash lasts with no diagnosis, think of body-wide disease and test for it.
CFPC skill Clinical reasoning, procedure skillsPhase Hypothesis generation, investigation, follow-upSources Choosing Wisely Canada
On the exam
A scaly ring in the groin is no better after months of a steroid-antifungal cream. Expect a short menu (pick several from a list) of next steps.
Pick the tests and next steps.
Common mistakes
Another cream, or stopping after one normal test. A rash that will not settle needs a scraping, a biopsy or a referral, even when early tests are normal.
Approach
- Think of body-wide disease: lupus, diabetes, celiac disease, thyroid disease.
- Scaly rash that could be fungal: scrape it to confirm fungus before you treat it.
- Nail changes: confirm fungus by microscopy, culture or biopsy before an oral antifungal. Many nail changes are not fungal.
- Pustules or crusts: swab for culture. Blisters: swab for viruses.
- No clear diagnosis, or a sore that will not heal: take a punch biopsy.
- Order blood tests the picture points to: glucose or A1c, celiac antibodies, antinuclear antibodies (ANA), thyroid tests.
- Normal results do not end the search. Refer to dermatology if the rash goes on.
Key feature 6 of 8
How it affects life
With a rash that lasts or returns, ask how it affects daily life and mood.
CFPC skill Patient-centred approachPhase History, follow-up
On the exam
A teen with eczema says the skin is fine but has stopped going out with friends. Expect a short menu (pick several from a list) of things to ask.
Pick what to ask about.
Common mistakes
Judging the rash by its size and moving on. Mild-looking skin disease can bring shame, poor sleep, missed school or work, and low mood.
Approach
- Ask about itch, sleep, school or work, sport and intimacy.
- Ask how the patient feels about how the skin looks, and whether they avoid people.
- Screen for low mood and anxiety. If mood is low, ask about thoughts of self-harm.
- In a child, ask about teasing and how the family copes with the care routine.
- Set goals together, based on what bothers the patient most.
Key feature 7 of 8
Why it keeps coming back
When a rash lasts or returns, look for triggers, missed treatment and products that hide or worsen it.
CFPC skill Clinical reasoning, patient-centred approachPhase Hypothesis generationSources Choosing Wisely Canada
On the exam
Hand dermatitis keeps coming back despite a steroid cream. Expect a short menu (pick several from a list) of history questions.
Pick the questions that find the cause.
Common mistakes
A stronger steroid without asking why. The cause may be a work irritant, a cream used wrongly, or a product that itself causes allergy.
Approach
- Ask about work, hobbies, hand washing, gloves, soaps, cosmetics, hair dye and jewellery.
- Ask how the cream is used: how much, how often, for how long, and whether it ran out.
- Ask about worries over steroid creams. Fear can make people stop early.
- Ask about products from the pharmacy, online or at home: numbing creams, antibiotic ointments, home remedies.
- A steroid-antifungal combination cream can thin the skin and works less well than an antifungal alone. Avoid it on the face and in skin folds.
- Antibiotic ointment on a stitched wound can cause contact allergy. Keep antibiotics for a wound that shows signs of infection.
Key feature 8 of 8
Infectious rash
When a rash is catching, limit spread and tell public health when required.
CFPC skill Clinical reasoning, selectivity, professionalismPhase Treatment, follow-up
On the exam
A probable meningococcal case has a pregnant household contact. Expect one best answer for how to protect her.
Pick the right step for the contact.
Common mistakes
Waiting for culture proof, or offering her a vaccine alone. A vaccine cannot clear carriage now. Picking the usual adult drug without checking it in pregnancy is wrong too.
Approach
- Act on a suspected case. Contacts do not wait for the culture.
- Call public health now. Close contacts need antibiotic prophylaxis, arranged with them.
- In pregnancy, choose a prophylaxis drug that is safe for her. Ask public health or a pharmacist which one.
- A vaccine may follow once the germ's group is known. It protects later; it does not replace prophylaxis.
- Suspected measles: mask the patient and move them to a closed room at once.
- Report suspected measles or meningococcal disease to public health. Do not wait for lab proof.
- Chickenpox, impetigo or scabies: advise on hand washing, keeping away from others, and treating the household if needed.
Flashcards
Answer it first, then check.
KF 1A patient with fever has new dark spots. Which bedside check matters most?
Press on them. Spots that do not fade, with fever, mean sepsis until proven otherwise.
KF 2Both lower legs are red and swollen, with no fever. Is it cellulitis?
Probably not. Think of stasis dermatitis. Redness of both legs does not call for routine antibiotics. Source: Choosing Wisely Canada
KF 3Flat purple spots do not fade with pressure. What do you call them?
Purpura, or petechiae if they are pinpoint. Write that in the note, not “red rash”.
KF 4Fever, low blood pressure and spreading purpura. Head CT before antibiotics?
No. Give IV antibiotics now. A scan or a lumbar puncture must never delay them.
KF 4Painful skin, blisters and mouth sores a week after a new drug. What next?
Think of Stevens-Johnson syndrome. Stop the drug and send the patient to hospital today.
KF 5A scaly ring rash. What do you do before you prescribe an antifungal?
Take a skin scraping to confirm fungus. Avoid steroid-antifungal combination creams as a routine. Source: Choosing Wisely Canada
KF 7Eczema is no better on a steroid cream. What do you ask first?
How it is used: how much, how often, and whether the patient still uses it.
KF 8A probable meningococcal case. Wait for the culture before treating contacts?
No. Call public health now. Close contacts need antibiotic prophylaxis without delay.
FAQ
Which Canadian guideline covers rash?
No single Canadian guideline covers rash. The exam tests a method: vital signs first, clear words, pattern spotting, tests for a rash that persists, and fast action on danger signs.
Which skin terms do I need to know?
Know the core ones: macule, patch, papule, plaque, vesicle, bulla, pustule, petechiae and purpura. Add shape, layout and site. Clear words let another doctor picture the rash.
When should I biopsy a rash?
When a rash persists without a clear diagnosis, or fails treatment used properly. Never let a biopsy delay antibiotics in a sick patient with fever and spreading purpura.
Which infectious rashes do I report?
Report the diseases your province lists, such as measles and invasive meningococcal disease. Call about suspected cases. Public health traces contacts and advises on prophylaxis and vaccine.
Sources
Written from the CFPC Assessment Objectives and Canadian guidelines first. Checked by a Canadian family physician, MD, CCFP.
Last reviewed October 20, 2026For exam study. Not advice for a patient in front of you.
- Assessment Objectives for Certification in Family Medicine, 2nd editionCollege of Family Physicians of Canada · 2020
- Choosing Wisely recommendationsChoosing Wisely Canada