| | scale, hyperkeratosis or crust usually present | |
Typically annular lesions | common/fairly common causes | - ringworm (scaling particularly at margin)
- porkeratosis (keratotic border)
- pityriasis rosea - herald patch
| - granuloma annulare
- Jessner's lymphocytic infiltrate
- morphoea (not annular lesions but often has annular violaceous margin)
|
| | - erythema annulare centrifugum
- subacute cutaneous lupus erythematosus
- pigmented purpuric dermatoses (fine scale only)
- linear IgA disease, chronic bullous dermatosis of childhood
- actinic granuloma
- eczema surround a naevus (Meyerson's naevus)
| - purpura annularis telangiectodes
- serum sickness and serum sickness-like drug eruption
- erythema (chronicum) migrans
- 'annular erythemas' with deeply situated infiltrate
|
Often includes some annular or incompletely annular (arciform) lesions | common/fairly common causes | - psoriasis
- bullous pemphigoid
- seborrhoeic dermatitis of the trunk
- subacute cutaneous lupus erythematosus (papulosquamous/psoriasiform type)
- impetigo
| - urticaria
- erythema multiforme
- lichen planus (particularly male genital) *
|
| | - mycosis fungoides
- atopic dermatitis **
| - cutaneous sarcoidosis*
- B-cell lymphoma of skin
|
* some typically non-scaling disorders may occur as less common variants with scale
** atopic dermatitis is common, but discoid or annular lesions are relatively uncommon
Reference:
- (1) Smith LC et al. A guide to annular eruptions. Dermatology in Practice (April 2008); 16(1).