Annular lesions on the trunk include the chest ,back and abdomen.
Acute onset lesions include Urticara(lasting less than 24 hrs),Erythema chronicum migrans,Erythema annulare centrifugum.Slowly expanding lesions with a scaly edge suggests Tinea corporis or psoriasis.Subacute lupus erythematosus is seen on the upper back and chest as well as other sunexposed areas.A solitary annular lesion may be the herald patch of Pityriasis rosea.
Management - skin scrapings, check to see if there is a loss of sensation which would be seen in leprosy in the centre of the lesion and biopsy if you consider one of the granulomatous diseases.
SIGN DIP MEN Overview of Annular lesions
S-Squamous Resolving psoriasis,Discoid eczema, Lichen simplex chronicus, Genital lichen planus,Herald patch of Pityriasis rosea,
I-Infective Tinea (Ringworm),Erythema chronicum migrans,Leprosy,Syphilis,Erythema marginatum,
G-Granulomatous Granuloma annulare,Sarcoidosis,Elastolytic granuloma
N-Neoplastic Basal cell skin cancer,Mycosis fungoides,follicular mucinosis,Erythema gyratum repens,Necrolytic migratory erythema,Porokeratosis of Mibelli
D-Drugs Reactive annular erythema after Vit K injections,can also occur after heparin,collagen steroid and anticancer agent injections,
I-Immunological Urticaria,Angioedema,Subacute lupus erythematosus,Neonatal lupus erythematosus,
P-Physical Cupping,ECG suction caps,
M-Metabolic Reticular erythematous mucinosis
E-Endocrine
N-Nutritional
Others - Annular erythema of infancy,
Annular red brown lesions with scale and central scar Tertiary syphilis,lupus vulgaris,lupus erythematosus,sarcoidosis,cicatricial pemphigoid,leishmaniasis(purplish scar in recidivans)