Thursday, October 23, 2008

Annular lesions

Annular lesions are always fun to diagnose. The public invariably diagnose them as tinea or ringworm but that diagnosis is only a possibility if there is scale. If there is no scale then the process is dermal and you should consider granuloma annulare, sarcoidosis, annular erythema and even leprosy!

Annular lesions on the face

Tinea faciei due to a dermatophyte infection would be the commonest, but granulomatous disorders such as sarcoidosis and granuloma annulare and infective conditions such as leprosy should also be considered.

Management - skin scrapings if scaly, 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,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



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)