Links to pages about skin conditions that favour the trunk.
- Erythema
- Red papules/pustules
- Erosions, crusting
- Dry scaly and itchy
- Dry scaly but not very itchy
- Skin coloured papules
- Pigmentary changes
Trunk: erythema without surface change
Erythema is less pronounced in dark skin.
- Intermittent redness eg when hot, embarrassed or with certain foods
- Often lifelong tendency
- Systemically well
- May precede/accompany rosacea
- Sun-exposed site
- Painful
- Consider phototoxic drugs
- Weals can arise on any site
- Spontaneous and inducible types
Trunk: red papules/pustules
- Upper trunk
- Open and closed comedones
- Nodules + cysts if severe
- Bathing costume distribution
- Exposed to hot tub
- Papulopustules
- Rarely, fever
- Lower back
- Firm, violaceous papules + white streaks
- Favours areas of earlier injury
- Also examine mouth, distal limbs
- Upper trunk
- Monomorphous superficial papulopustules
- Mid trunk
- Acute non-follicular papulopustules
- Follows heat/sweating
- Entire trunk spreading to limbs
- Commenced new drug within 10 days
- Monomorphic macules and papules
- Variable itch
Trunk: erosions/crusting
- Dermatomal
- Painful
- Erythema may precede vesicles
- Culture/PCR: Herpes varicella zoster
- Irregular enlarging plaque
- Honey-coloured crusts
- Culture: Staphylococcus aureus +/- Streptococcus pyogenes
Scabies rash
- Burrows between fingers, wrists
- Nodules in axillae, groin
- Intense itch, especially at night
- Dermatoscopy of burrow reveals mite
Transient acantholytic dermatosis / Grover disease
- Acute or chronic
- Itchy or asymptomatic
- Elderly males
- Crusted papules
- Febrile illness
- Also involves face, oral mucosa
- Monomorphic eruption
- Culture/PCR: Herpes varicella zoster
Trunk: dry/scaly + very itchy
May also blister, swell.
- Acute flares on any site
- Asymmetrical, odd-shaped patches/plaques
- Patch tests positive
- Patchy or diffuse
- Acute flares are erythematous
- Chronic eczema is lichenified
- Coin-shaped plaques
- Consider autoeczematisation from other site
Secondary syphilis
- Rash involves palms, soles
- Positive syphilis serology
Trunk: dry and scaly with minimal itch
- Slowly enlarging rings
- Scale just inside periphery
- Distribution along Langers lines (fir tree pattern)
- Larger herald patch appears several days before others
- Oval shaped plaques with scale just inside periphery
- Variable itch
- Mid-upper back and mid chest
- Pale, pink or brown macules, patches
- Diffuse bran-like scale
- Mycology microscopy negative, culture positive
- Roughly symmetrical distribution
- Well-circumscribed erythematous scaly plaques
- Variable itch
- Mid-upper back and mid chest
- Erythema, flaking
- Skin feels rough on palpation
- Often, follicular prominence
Subacute cutaneous lupus erythematosus
- Upper trunk
- Thin erythematous plaques
- Peripheral scale
- Check CBC, ANA, ENA
- Biopsy confirmatory
- Asymmetrical annular or discoid shaped plaques
- Peripheral scale
- Mycology microscopy + culture positive
Trunk: multiple skin coloured papules
- Open and closed comedones
- Folliculocentric
- Arranged in rings
- Genodermatosis
- Superficial pseudocysts
Pigmentary changes
Pigmentation is more pronounced in dark skin.
- Preceding eczema, psoriasis, acne etc
- Distribution depends on cause
See also pigmentary disorders