Scaly skin conditions

Skin diseases that have excessive scale or flaking (papulosquamous disorders) are due to epidermal inflammation or proliferation. We list localised and generalised scaly skin disorders by their duration and body site.

Localised scaly rash present for < 6 weeks

Dermatophyte infections

Irregular annular rash with peripheral scale
Acute forms of tinea may also have follicular pustules
Tinea corporis – trunk, limbs
Tinea cruris – groin
Tinea pedis – feet
Tinea manuum – hands
Tinea faciei – face

Generalised scaly rash present for <6 weeks with fever

Scarlet fever

Scarlatiniform rash (redness then rough spots)
Strawberry tongue
Peeling starts after 5 days of illness
Evidence of streptococcal infection

Kawasaki syndrome

Child aged < 14 years
Starts as morbilliform or erythematous rash
Swelling of hands and feet
Oral and ocular signs
Lymphadenopathy

Exfoliative dermatitis

Scaling stage of erythroderma
Starts as morbilliform rash or other pattern
Often drug-induced

Generalised scaly rash present for < 6 weeks without fever

Pityriasis rosea

Herald patch
Oval 2–4 cm pink plaques on trunk with peripheral, trailing scale
Spares scalp, peripheries

Acute guttate psoriasis

Round 0.5–3 cm red plaques with diffuse scale
Trunk > limbs
May involve all body sites

Pityriasiform or lichenoid drug eruption

New drug (eg hydroxychloroquine)

Localised scaly rash present for > 6 weeks

Seborrhoeic dermatitis

In and around hair-bearing scalp, eyebrows, hairy chest
Skin folds behind ears, nasolabial fold, axilla
Salmon pink, flaky

Psoriasis

Localised variant
Scalp, elbows, knees or palms and soles

Discoid lupus erythematosus

Face, ears, scalp > upper trunk, hands
Scale is due to plugged follicles
Leads to scarring

Pityriasis versicolor

Flaky rash on trunk
White, red, brown variants

Keratosis pilaris

Upper arms > thighs > cheeks
Hair follicles plugged with scale

Annular erythema

Crops of slowly enlarging erythematous annular plaques on trunk
Trailing scale

Palmoplantar keratoderma

Thickened skin of palms and soles
Congenital and acquired, punctate and diffuse variants

Crusted scabies

Scale is prominent between fingers, elbows, scalp
May or may not be very itchy
Contacts have scabies

Widespread tinea corporis

Irregular annular plaques
Peripheral scale

Ichthyosis

Dry skin (see below)

Chronic plaque psoriasis

Symmetrical well-circumscribed plaques with silvery scale
Generalised large or small plaques

Lichen planus

Bilateral but asymmetrical firm papules, plaques
Polygonal shape
Scale is variable

Pityriasis lichenoides

Trunk and limbs
Skin coloured or red flat or indurated papules/small plaques
Mica scale (peels off in one sheet)

Pityriasis rubra pilaris

Psoriasis-like symmetrical or erythrodermic scaly rash
Orange-red hue
Follicular prominence

Cutaneous T cell lymphoma

Slowly evolving slightly scaly annular and roundish patches, plaques and sometimes nodules
Various morphologies including erythroderma
Buttocks, breasts common initial sites

Dermatitis neglecta

Build-up of scale due to avoidance of washing

Scaly condition by body site

Solitary scaly lesions

Actinic (solar) keratoses
Basal cell carcinoma (superficial)
Bowen disease (intraepidermal squamous cell carcinoma)
Squamous cell carcinoma
Keratoacanthoma