Arms and Legs Plaques

The commonest causes of plaques on the Arms and Legs 

Many of the lesions below can present as plaques on the arms and legs. There is no easy clinical way to separate them except by knowing the nature of the diseases.Psoriasis and skin cancers are common in white populations.A unilateral spreading plaque with a scaly edge may be tinea.Mycosis fungoides gives fixed slowly growing plaques that spread and thicken.Discoid eczema is itchy and oozes. Discoid or subacute lupus will give both scaly and nonscaly plaques. Consider polymorphous light eruption if in sun exposed areas or a photo drug reaction. All the major infective causes can form plaques as well as papules and nodules.Watch for the unusual lesions such as Sweet's syndrome.An itchy plaque over the shin is likely to be Lichen simplex chronicus.An indurated thick plaque in the same area could be pretibial myxoedema.If you are stumped take a skin biopsy.

SIGN DIP Overview of Plaques

Plaques are essentially grouped papules that coalesce or they are infiltrates or deposits in the skin.So many of the papular disorders can form plaques and many of the nodular disorders have the same differentials.

S Squamous Psoriasis,Pityriasis rubra pilaris,Tinea barbae,Discoid eczema,Epidermal nevus,Sebaceous nevus,Discoid lupus

I Infective   Deep fungus,Tinea barbae,Leishmaniasis,Tuberculosis,Leprosy,  Acanthameba,  Post erysipelas ,Cellulitis ,Post rosacea,Plasma cell balanitis,   

G Granulomatous Actinic granuloma,Granuloma annulare,Necrobiosis lipoidica,Granuloma faciale,Erythema elevatum diutinum,Sarcoidosis

N Neoplastic Mycosis fungoides,Basal cell skin cancer,Paget’s and extramammary Paget’s disease,Lymphocytoma,Lymphoma,Jessners lymphocytic infiltrate,Parapsoriasis,Mycosis fungoides,Metastases,Kimura's disease,Angiosarcoma,Follicular mucinosis,Amyloidosis,

D Drug Sclerosant injection,Fixed drug reaction,Vitamin K injection,

I Immunological  Urticaria,Discoid lupus erythematosus,Lupus panniculitis,Localised morphea,Lichen sclerosus,Scleredema,Scleroderma,Eosinophilic fasciitis,Eosinophilic cellulitis,Urticarial vasculitis,

P Physical  Post traumatic,Polymorphous light eruption,

Syndromes Blooms syndrome,Familial mediteranean fever,Reticular erythematous mucinosis,Sweet’s syndrome,Well’s syndrome,Erythema elevatum diutinum,