Differentiating erysipelas from other diseases

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Luke Rusowicz-Orazem, B.S.

Overview

Erysipelas must be differentiated from other inflammatory dermatological conditions that present with pain, erythema, edema, and blisters of the skin, as well as other systemic conditions such as fever, chills, fatigue, headache, and vomiting.

Differentiating Erysipelas from other Diseases

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

Diseases	Symptoms							Signs	Gold standard Investigation to diagnose
	History	Onset	Pain	Fever	Laterality	Scrotal swelling	Symptoms of primary disease
(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.
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
Myxedema	History of untreated hypothyroidism. Infiltration of the skin with glycosaminoglycans with associated water retention.	Chronic	+	-	Bilateral	-	+ (hypothyroidism )	Pretibial myxedema	Thyroid function tests.
Other causes of generalized edema	History of chronic general condition (cardiac-liver-renal)	Chronic	-	-	Bilateral	-	+		According to the primary cause ( Echo- LFTs- RFT)

• Erysipelas must be differentiated from other inflammatory dermatological conditions that present with pain, erythema, edema, and blisters of the skin, as well as other systemic conditions such as fever, chills, fatigue, headache, and vomiting.

Disease	Findings
Cellulitis	Presents with nearly identical symptoms to erysipelas, and is also usually caused by Streptococcus or Staphylococcus bacteria. Differentiated from erysipelas by its manifestation beneath the epidermis in the dermal layer of the skin; infection can spread to the subcutaneous fat, bones, joints, and muscles of the affected area. The area of inflammation is not as sharply visibly demarcated as those characteristic of erysipelas, due to the deeper manifestation in the skin. Can lead to complications with poor prognosis including osteomyelitis, lymphangitis, endocarditis, and meningitis.
Necrotizing fasciitis	Presents with more severe epidermal signs and symptoms than erysipelas. Necrotizing fasciitis patients usually present with erythema, edema, blisters, pain, suppuration, and clear signs of tissue necrosis (dark violet/blue to black in appearance). Left untreated, necrotizing fasciitis usually leads to subcutaneous nerve destruction; a patient communicating more pain than is visibly apparent or manifested on the epidermis is indicative of nerve damage preceding or disproportionate to visible evidence. In addition to antibiotics, immediate therapeutic surgery is required to prevent morbidity from necrotizing fasciitis.
Shingles	Presents with itching, pain, and tingling on a single side of the body or face, which will develop into a rash with blisters. It can also present with fever, chills, headache, and nausea.. Differentiated from erysipelas by its cause (Varicella zoster virus infection) and is usually self-limited; antiviral therapy and analgesics are indicated to shorten the duration and severity of symptoms, which will usually self-resolve within 7-10 days. Recognition and diagnosis of shingles is important to prevent complications, including postherpetic neuralgia.
Angioedema	An edematous condition that involves swelling occurring below the epidermis, including the dermis and mucous membranes. Angioedema usually presents with edema near the eyes and lips, as well as the hands, feet, and throat. Can present similarly to erysipelas if epidermal welts and blisters form in the regions of edema, as well as cause abdominal pain. Differentiated from erysipelas in that the cause is primarily an allergic reaction to a variety of possible allergens, including pollen, food, or medication. While angioedema is usually self-limited and will resolve itself upon the cessation of exposure to the allergen, treatment with antihistamines, epinephrine, or corticosteroids must be administered to prevent life-threatening complications, including asphyxiation if the edema occurs in the throat.
Contact dermatitis	An inflammatory condition of the epidermis resulting from direct contact with an allergen or irritant. Contact dermatitis is similar to erysipelas due to the usual presentation of erythema, blisters, itching, pain, and discharge. Differentiated from erysipelas by its cause: an allergic response by contact to a specific surface or entity. There is no indication of bacterial infection. Common causes include chemicals from cosmetic and hygienic products, fabrics, metals, and animal hair or skin. Therapy involves avoiding the original cause and application of topical or oral corticosteroids and analgesics.
Inflammatory breast cancer	Presents with edema and erythema of the breast, as well as itching, pain, and tenderness from the inflammation. Differentiated from erysipelas by the fact that inflammation is usually limited to the breast. Additional differential criteria include development of "ridges" on the breast, giving the appearance of an orange peel. It is urgent to differentiate and diagnose inflammatory breast cancer to begin immediate chemotherapy, radiation therapy, and/or surgery when indicated.