Myxedema coma differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] ; Associate Editor(s)-in-Chief: Aditya Ganti M.B.B.S. [2]

Overview

Myxedema must be differentiated from other causes of lower limb edema like chronic venous insufficiency, acute deep venous thrombosis, lipedema, lymphatic filariasis, cellulitis and causes of generalized edema.

Differential Diagnosis

Myxedema must be differentiated from other causes of lower limb edema like chronic venous insufficiency, acute deep venous thrombosis, lipedema, lymphatic filariasis, cellulitis and causes of generalized edema.

Diseases	History	Symptoms						Signs	Gold standard Investigation to diagnose
		Onset	Pain	Fever	Laterality	Scrotal swelling	Symptoms of primary disease
Myxedema	History of untreated hypothyroidism Infiltration of the skin with glycosaminoglycans with associated water retention	Chronic	+	-	Bilateral	-	+ (hypothyroidism )	Pretibial myxedema	Thyroid function tests
Lymphatic filariasis	History of living in endemic area or travelling to it	Chronic	+	+	Bilateral	+	-	Hepatomegaly Lymphedema Elephantiasis Lymphangitis Hydrocele Scrotal elephantiasis Lymphadenopathies Rhonchi may be present in patients with Pulmonary tropical eosinophilia syndrome	Preparing blood smears Thick smears Thick smears consist of a thick layer of dehemoglobinized (lysed) red blood cells (RBCs) Thick smears allow a more efficient detection of parasites (increased sensitivity) Thin smears consist of blood spread in a layer such that the thickness decrease By the ultrasound, the following findings can be observed: Dilated lymphatic channels Living worms tend to be in motion which called "filarial dance" sign.
Chronic venous insufficiency	History of untreated varicose veins Painful bilateral lower limb swelling that increases with standing and decreases by rest and leg elevation	Chronic	+	-	Bilateral	+ (If congenial)	-	Typical varicose veins Skin change distribution correlate with varicose veins sites in the medial side of ankle and leg Reduction of swelling with limb elevation	Duplex ultrasound will demonstrate typical findings of venous valvular insufficiency
Acute deep venous thrombosis	History of prolonged recumbency Classic symptoms of DVT include acute unilateral swelling, pain, and erythema	Acute	+	-	Unilateral	-	May be associated with primary disease mandates recumbency for long duration	Dilated superficial veins Difference in calf diameter is twice as likely to have DVT(most impotant sign ) Calf pain on passive dorsiflexion of the foot (Homan's sign) isn't realiable sign	Compression ultrasonography (CUS) with doppler is the diagnostic test of choice D-dimer level is used for unprobable cases
Lipedema	Family history especially in women; X-linked dominant or autosomal dominant condition Abnormal deposition of fat and edema and easy bruising	Chronic	+	-	Bilateral	-	-	Tender with palpation Negative Semmer sign to differentiate from lymphedema Pinching the skin on the upper surface of the toes If it is possible to grasp a thin fold of tissue then it is negative result In a positive result, it is only possible to grasp a lump of tissue.	MRI offers strong qualitative and quantitative parameters in the diagnosis of lipedema
(Cellulitis-erysipelas-skin abscess)	Acute painful swelling Fever	Acute	+	+	Unilateral	-	-	Tenderness, hotness, and may be fluctuation if abscess formed Lymphangitis in nearby lymph nodes Toxemia and fever in severe cases Cellulitis involves the deeper dermis and erysipelas involves the upper dermis	Usually it doesn't need any laboratory tests to diagnose Blood cultures are warranted for patients in the following circumstances: Systemic toxicity Extensive skin or soft tissue involvement Underlying comorbidities Persistent cellulitis In patients with recurrent cellulitis, serologic testing for beta-hemolytic streptococci is a good diagnostic tool
Other causes of generalized edema	History of chronic general condition (cardiac-liver-renal)	Chronic	-	-	Bilateral	-	+		According to the primary cause ( Echo- LFTs- RFT)