The type is not a label — it changes the treatment. Guttate disease often clears completely with light; inverse disease is ruined by the same treatment that helps plaques; pustular disease can be a medical emergency.
Raised, sharply bordered plaques with silvery scale. Elbows, knees, lower back and scalp are classic sites, usually symmetrically.
A sudden shower of small spots across the trunk and limbs, typically one to three weeks after a streptococcal throat infection.
Smooth, shiny red areas in the armpits, groin, under the breasts and between the buttocks. Little or no scale, because the fold keeps it moist.
| Type | What it looks like | Why it matters |
|---|---|---|
| Nail psoriasis | Pitting, oil-drop discolouration, lifting, crumbling | Strongly associated with psoriatic arthritis; treat and screen |
| Scalp psoriasis | Thick adherent scale, often past the hairline | Very common; needs descaling before anything else will penetrate |
| Palmoplantar | Thickened, fissured palms and soles | Small area, large disability — affects work and walking |
| Pustular (localised) | Sterile pustules on palms or soles | Not infection; often linked to smoking |
| Generalised pustular | Widespread pustules with fever and malaise | A medical emergency — same-day assessment |
| Erythrodermic | Redness and scaling over most of the body | Emergency — risk of fluid, temperature and infection problems |
The last two rows are the reason this page names them. Both are uncommon, both can follow abrupt withdrawal of oral steroids, and both need urgent care rather than a routine appointment.
Inverse psoriasis treated as a fungal infection gets antifungals for months and does not improve. Nail psoriasis treated as onychomycosis gets oral antifungals with liver monitoring for a disease it does not have. Scalp psoriasis treated as dandruff gets a shampoo that cannot penetrate the scale.
All three are ordinary, frequent errors, and all three are settled by examination — looking for psoriasis elsewhere on the body, checking the nails, and looking at the scale rather than the redness.
Telling scalp psoriasis from dandruffNail changes in someone with an unclear rash frequently settle the diagnosis — and flag arthritis risk at the same time.
A single confusing patch in a fold is much easier to name when there are typical plaques on the elbows.
Yes, and it is common — plaque psoriasis with scalp and nail involvement is probably the most frequent combination seen in clinic.
Sometimes. Many first episodes clear completely and never return. A proportion of people go on to develop chronic plaque disease later, but a single guttate episode is not a guarantee of that.
Most likely because it is in a body fold. Inverse psoriasis stays moist, so it looks smooth and red rather than silvery — and is often mistaken for a fungal infection as a result.
Yes, though it is slow because nails grow slowly — expect to judge results over six to twelve months. It matters beyond appearance, because nail disease is associated with psoriatic arthritis.
Redness and scaling covering most of the body, or widespread pustules with fever and feeling unwell. Both need same-day medical assessment rather than a routine clinic appointment.
Not a treatment plan sold on the spot. Message the clinic and bring your history.