Erysipelas: Symptoms, Causes & Treatment Guide

What Is Erysipelas and What Causes It?

Erysipelas is an acute bacterial skin infection affecting the upper dermis and superficial lymphatics, caused primarily by Group A Streptococcus (Streptococcus pyogenes). The bacteria enter through breaks in the skin such as wounds, ulcers, or cracks, multiply rapidly, and cause inflammation that spreads through the lymphatic vessels, producing the characteristic sharply demarcated red rash.

Erysipelas, sometimes called "St. Anthony's Fire" due to its fiery red appearance, is one of the oldest recognized skin infections in medical history. Unlike cellulitis, which affects deeper skin layers, erysipelas involves the more superficial dermis and lymphatic vessels, which gives it its distinctive raised, sharply demarcated border. This superficial involvement also explains why erysipelas often appears more clearly defined than cellulitis, making clinical diagnosis relatively straightforward in typical cases.

The condition affects approximately 10 to 100 people per 100,000 population annually, with higher rates seen in elderly individuals, those with compromised immune systems, and people with conditions that impair skin integrity or lymphatic drainage. While erysipelas can occur at any age, the peak incidence is in adults over 60 years old, and it affects both sexes relatively equally, though some studies suggest a slight female predominance.

Understanding the pathophysiology of erysipelas helps explain its clinical features. When bacteria gain entry through a break in the skin barrier, they begin multiplying in the superficial dermis. The bacteria produce various toxins and enzymes that damage tissue and trigger an intense inflammatory response. This inflammation spreads rapidly through the superficial lymphatic vessels, causing the characteristic bright red discoloration and warmth of the overlying skin. The sharp borders occur because the infection spreads primarily through lymphatic channels rather than diffusely through tissue.

The Role of Bacteria in Erysipelas

Group A Streptococcus (GAS), specifically Streptococcus pyogenes, is responsible for the vast majority of erysipelas cases, accounting for approximately 80-90% of infections. These bacteria commonly colonize the skin and throat in healthy individuals without causing problems. However, when they breach the skin barrier and enter the dermis, they can cause significant infection.

Streptococcus pyogenes possesses several virulence factors that contribute to its ability to cause erysipelas. M protein on the bacterial surface helps the organism evade the immune system by preventing phagocytosis by white blood cells. The bacteria also produce various exotoxins, including streptococcal pyrogenic exotoxins, which contribute to fever and systemic symptoms. Enzymes such as streptokinase and hyaluronidase help the bacteria spread through tissues by breaking down clots and connective tissue components.

In some cases, other bacteria may cause erysipelas or erysipelas-like infections. Group B, C, and G streptococci can occasionally be responsible, particularly in patients with diabetes or other immunocompromising conditions. Staphylococcus aureus, including methicillin-resistant strains (MRSA), may rarely cause similar presentations, though these infections typically have features more consistent with cellulitis or abscess formation.

Entry Points for Infection

Bacteria require a break in the skin barrier to cause erysipelas. Common entry points include:

• Leg ulcers and chronic wounds: These provide ongoing opportunities for bacterial invasion and are a major risk factor for lower extremity erysipelas
• Athlete's foot (tinea pedis): The cracks and fissures between toes from fungal infection create perfect entry points for bacteria
• Eczema and dermatitis: Disrupted skin barrier from inflammatory skin conditions allows bacterial entry
• Insect bites and scratches: Even minor trauma can provide sufficient breaks in the skin
• Surgical wounds: Post-operative infections can manifest as erysipelas
• Dry, cracked skin: Fissures from dry skin, particularly on the feet and lower legs, are common entry points

What Are the Symptoms of Erysipelas?

Erysipelas symptoms include a rapidly spreading bright red, hot, and painful skin rash with sharp, raised borders. The affected area typically appears within hours and can grow several centimeters in a single day. Systemic symptoms such as fever (often 38-40°C/100-104°F), chills, fatigue, and nausea frequently accompany the skin changes, sometimes appearing before the rash becomes visible.

The hallmark of erysipelas is its distinctive appearance. The affected skin becomes intensely red with a well-defined, raised border that is easily distinguishable from surrounding normal skin. This sharply demarcated edge is one of the key features that differentiates erysipelas from cellulitis, which typically has less distinct borders. The surface of the affected skin often has a characteristic "peau d'orange" (orange peel) texture due to swelling around hair follicles.

Pain is a prominent feature of erysipelas. The affected area becomes tender to touch and may throb or burn. The intensity of pain often correlates with the degree of inflammation and can be significant enough to limit mobility, particularly when the legs are affected. Swelling accompanies the redness and can be substantial, sometimes causing the skin to appear shiny and taut.

The rapid progression of symptoms is notable. Many patients can pinpoint almost exactly when their symptoms began because the onset is often sudden. The redness spreads visibly over hours, sometimes advancing several centimeters per day. This rapid spread reflects the movement of bacteria through the superficial lymphatic vessels. Some patients describe being able to watch the red border move outward over the course of a day.

Systemic Symptoms

Unlike many localized skin infections, erysipelas frequently causes significant systemic symptoms. These constitutional symptoms reflect the body's response to bacterial toxins and inflammation:

• Fever: Body temperature often rises to 38-40°C (100-104°F), sometimes higher. Fever may precede visible skin changes by several hours
• Chills and rigors: Shaking chills, sometimes severe, are common and may be the first symptom noticed
• Malaise: A general sense of being unwell, fatigue, and weakness
• Nausea and vomiting: Gastrointestinal upset may accompany the infection
• Headache: Often accompanies fever
• Loss of appetite: Decreased desire to eat during acute illness

Importantly, systemic symptoms often appear before obvious skin changes become apparent. A patient might experience sudden onset of high fever and feel very unwell, only to notice redness developing hours later. This prodrome can sometimes lead to initial misdiagnosis as a viral illness before the characteristic rash appears. Healthcare providers should maintain a high index of suspicion for erysipelas in patients presenting with sudden fever and localizing pain, even before the rash is clearly visible.

Location of Erysipelas

While erysipelas can occur anywhere on the body, certain locations are more commonly affected:

Lower extremities (70-80% of cases): The legs are by far the most common site for erysipelas. Risk factors specific to leg involvement include venous insufficiency, lymphedema, previous leg surgery (including saphenous vein harvest for bypass surgery), and pre-existing skin conditions affecting the lower legs. The infection often starts around the ankle or lower leg and spreads upward.

Face (5-20% of cases): Facial erysipelas often follows upper respiratory infections and may start near the nose or ear. It can spread across the face in a characteristic "butterfly" pattern. Facial erysipelas is more common in children than adults and carries risks of complications involving the orbit or central nervous system in severe cases.

Arms and other sites: Less commonly, erysipelas can affect the arms (particularly after breast surgery with lymph node removal), the trunk, or other body sites. The same principles of infection apply regardless of location.

When Should You See a Doctor for Erysipelas?

Seek medical care promptly if you develop a rapidly spreading red, hot, painful skin rash, especially with fever. Seek emergency care immediately if you have high fever (over 39°C/102°F), rapidly advancing redness, severe pain, signs of sepsis (confusion, rapid breathing, racing heart), or facial involvement near the eyes. Early antibiotic treatment is crucial for preventing complications.

Erysipelas is a serious bacterial infection that requires medical evaluation and antibiotic treatment. While it is highly treatable, delays in starting antibiotics can lead to complications and prolonged illness. The decision about when and where to seek care depends on the severity of symptoms, presence of risk factors for complications, and how quickly the infection appears to be progressing.

In general, anyone with symptoms suggestive of erysipelas should be evaluated by a healthcare provider within hours of symptom onset, not days. The infection spreads rapidly, and early treatment significantly improves outcomes. Most cases can be managed with oral antibiotics on an outpatient basis, but the diagnosis needs to be confirmed and appropriate treatment initiated promptly.

Seek Urgent Medical Care If You Have

• A rapidly spreading area of red, hot, painful skin
• Fever (temperature above 38°C/100.4°F) with skin changes
• Chills or rigors accompanying skin redness
• A red rash with a sharp, raised border
• Skin changes that have appeared and spread within hours

How Is Erysipelas Treated?

Erysipelas is treated with antibiotics, with penicillin being the first-line choice. Oral penicillin V (phenoxymethylpenicillin) is used for uncomplicated cases, while intravenous benzylpenicillin is given for severe infections or when oral medication cannot be taken. Treatment typically lasts 10-14 days. Most patients show improvement within 24-48 hours of starting antibiotics.

Antibiotic therapy is the cornerstone of erysipelas treatment. The excellent response of Group A Streptococcus to penicillin makes this the preferred antibiotic for most patients. Penicillin has been used successfully to treat erysipelas for decades, and resistance remains rare. The predictable response to penicillin also helps confirm the diagnosis - if a patient does not improve within 48-72 hours, the diagnosis should be reconsidered.

The choice between oral and intravenous antibiotics depends on the severity of infection, the patient's ability to take oral medications, presence of complicating factors, and whether outpatient management is appropriate. Most uncomplicated cases can be managed with oral antibiotics at home, with the patient returning for reassessment if symptoms worsen or fail to improve.

First-Line Antibiotic Treatment

Oral treatment (for uncomplicated cases):

• Penicillin V (phenoxymethylpenicillin): 500mg-1g four times daily for 10-14 days
• Amoxicillin: Alternative penicillin-type antibiotic, 500mg three times daily

Intravenous treatment (for severe cases):

• Benzylpenicillin (penicillin G): 1.2g-2.4g every 4-6 hours intravenously
• Can be switched to oral antibiotics once fever resolves and improvement is evident

For penicillin allergy:

• Clindamycin: 300-450mg four times daily
• Erythromycin or other macrolides: Alternative options
• Important to specify the type of allergic reaction to guide antibiotic choice

Supportive Care Measures

In addition to antibiotics, several supportive measures can help manage symptoms and promote healing:

Rest and elevation: Resting the affected limb and keeping it elevated above heart level when possible helps reduce swelling and improves comfort. For leg erysipelas, elevating the leg on pillows while lying down or sitting with feet up can make a significant difference in symptom relief.

Pain management: Over-the-counter pain relievers such as paracetamol (acetaminophen) or ibuprofen can help manage pain and reduce fever. Follow dosing instructions and be aware of any contraindications based on your medical history.

Cool compresses: Some patients find relief from applying cool, moist compresses to the affected area. Avoid ice directly on the skin, and do not apply anything that could further irritate or damage the skin.

Skin marking: Your healthcare provider may draw a line around the edge of the redness with a pen. This helps track whether the infection is spreading or improving. If the redness extends beyond the marked border despite antibiotic treatment, this indicates the infection is not responding adequately.

Expected Response to Treatment

With appropriate antibiotic therapy, most patients with erysipelas show significant improvement within 24-48 hours:

• Fever: Usually resolves within 24-72 hours of starting antibiotics
• Pain: Begins to improve within 24-48 hours, though some tenderness may persist longer
• Redness and swelling: Start to improve after 2-3 days but may take 1-2 weeks to fully resolve
• Skin changes: Some peeling or discoloration may persist for several weeks after the infection clears

Who Is at Risk for Erysipelas?

Risk factors for erysipelas include conditions that impair skin integrity (leg ulcers, eczema, athlete's foot), lymphatic damage (previous erysipelas, lymph node removal, radiation), venous insufficiency, obesity, diabetes, and immunocompromising conditions. People with previous episodes have a 20-30% risk of recurrence, with each episode further increasing future risk.

Understanding risk factors for erysipelas helps identify individuals who may benefit from preventive measures and explains why some people experience recurrent infections. Risk factors generally fall into categories related to skin barrier disruption, impaired lymphatic drainage, systemic conditions affecting immunity, and local anatomical factors.

Skin Barrier Disruption

Any condition that breaks the skin barrier creates potential entry points for bacteria:

• Chronic leg ulcers: Venous stasis ulcers, arterial ulcers, and diabetic foot ulcers provide ongoing access for bacteria
• Interdigital tinea pedis (athlete's foot): The maceration and fissuring between toes is a very common entry point
• Eczema and dermatitis: Inflammatory skin conditions compromise barrier function
• Psoriasis: Particularly when affecting the lower legs
• Dry, cracked skin: Xerosis (dry skin) with fissures, especially on the feet and heels

Lymphatic Impairment

Damage to the lymphatic system significantly increases erysipelas risk:

• Previous erysipelas: Each episode damages lymphatic vessels, increasing recurrence risk
• Lymph node removal: Axillary dissection for breast cancer increases arm erysipelas risk; groin dissection increases leg risk
• Radiation therapy: Can damage lymphatic vessels in the treatment field
• Primary lymphedema: Congenital lymphatic abnormalities
• Chronic venous insufficiency: Impairs lymphatic function over time

Systemic Risk Factors

• Diabetes mellitus: Impairs immune function and wound healing
• Obesity: Associated with increased infection risk and impaired lymphatic drainage
• Immunosuppression: HIV, organ transplant recipients, chemotherapy, immunosuppressive medications
• Alcohol use disorder: Associated with increased susceptibility
• Advanced age: Reduced immune function and skin integrity

How Can You Prevent Erysipelas?

Prevent erysipelas by maintaining good skin care: keep skin clean and moisturized, treat cuts and wounds promptly, manage underlying conditions like athlete's foot and eczema, protect skin from injury, and control risk factors like diabetes and edema. People with recurrent erysipelas may benefit from long-term prophylactic antibiotics.

Prevention strategies focus on maintaining skin integrity, reducing bacterial colonization, and managing modifiable risk factors. These measures are particularly important for individuals who have experienced erysipelas before, as recurrence rates are significant without preventive efforts.

Daily Skin Care

Moisturize regularly: Apply emollient cream daily, especially to the lower legs and feet, to prevent dry, cracked skin. Cracks in dry skin provide entry points for bacteria. Choose fragrance-free moisturizers and apply after bathing when skin is slightly damp.

Treat wounds promptly: Clean any cuts, scrapes, or breaks in the skin immediately with soap and water. Apply antiseptic and cover with a clean bandage. Keep wounds clean and dry until healed. Seek medical attention for wounds that appear infected or are not healing.

Manage fungal infections: Athlete's foot (tinea pedis) between the toes is a major risk factor for leg erysipelas. Treat fungal infections promptly with antifungal creams or powders. Keep feet clean and dry, and change socks regularly.

Control eczema and other skin conditions: Work with your healthcare provider to manage chronic skin conditions that compromise the skin barrier. Regular use of appropriate topical treatments and avoidance of triggers can help maintain skin integrity.

Managing Underlying Conditions

• Lymphedema management: Compression stockings, elevation, and massage therapy can help reduce swelling and improve lymphatic function
• Diabetes control: Good blood sugar management improves immune function and wound healing
• Venous insufficiency: Compression therapy and treatment of varicose veins may help
• Weight management: Reducing obesity can improve lymphatic drainage and reduce risk
• Smoking cessation: Improves circulation and wound healing

Antibiotic Prophylaxis

For individuals with frequent recurrent erysipelas (typically two or more episodes per year), long-term preventive antibiotics may be recommended. Common prophylactic regimens include:

• Penicillin V 250-500mg once or twice daily
• Erythromycin for penicillin-allergic patients
• Monthly intramuscular benzathine penicillin injections (in some settings)

Prophylaxis significantly reduces recurrence rates and is generally well-tolerated. The decision to use prophylactic antibiotics should be made in consultation with a healthcare provider, weighing the benefits against risks of long-term antibiotic use.

What Are the Potential Complications?

Complications of erysipelas include recurrence (20-30% risk), chronic lymphedema from repeated infections damaging lymphatic vessels, abscess formation requiring drainage, rarely sepsis (blood infection), and in facial cases, potential spread to the orbit or brain. Early treatment significantly reduces complication risk.

While most cases of erysipelas resolve completely with antibiotic treatment, complications can occur, particularly in delayed diagnosis, severe cases, or patients with underlying health conditions. Understanding potential complications helps emphasize the importance of prompt treatment and adequate follow-up.

Recurrent Erysipelas

Recurrence is the most common complication, affecting 20-30% of patients who have had one episode. Each episode of erysipelas damages the lymphatic vessels in the affected area, which paradoxically increases the risk of future episodes. This creates a cycle where repeated infections cause progressive lymphatic damage, leading to chronic swelling and ever-increasing recurrence risk.

Lymphedema

Progressive damage to lymphatic vessels from repeated or severe erysipelas can lead to chronic lymphedema (persistent swelling). Once established, lymphedema is difficult to treat and further increases infection risk. Managing lymphedema requires compression therapy, skin care, and often lifelong attention to prevent complications.

Abscess Formation

In some cases, pockets of pus (abscesses) may form within the infected tissue. These require drainage in addition to antibiotic therapy. Signs of abscess formation include a localized fluctuant (soft, movable) area within the infection, fever that persists despite antibiotics, or failure to improve with appropriate treatment.

Sepsis

Although uncommon with prompt treatment, bacteria from erysipelas can spread to the bloodstream, causing sepsis - a life-threatening systemic response to infection. Warning signs include high fever, rapid breathing, rapid heart rate, confusion, and feeling very unwell. Sepsis requires immediate emergency treatment with intravenous antibiotics and supportive care.

What Is the Difference Between Erysipelas and Cellulitis?

Erysipelas affects the upper dermis and has sharp, raised borders with a bright red "peau d'orange" appearance, usually caused by Group A Streptococcus. Cellulitis affects deeper skin layers, has indistinct borders, and can be caused by various bacteria including Staphylococcus. Both require antibiotic treatment, but cellulitis may need broader coverage.

Erysipelas and cellulitis are both bacterial skin infections that can appear similar, and the terms are sometimes used interchangeably. However, there are important clinical and microbiological differences that can influence treatment decisions.

In clinical practice, distinguishing between erysipelas and cellulitis can be challenging, and many infections have features of both. The practical importance lies mainly in antibiotic selection - pure erysipelas responds excellently to penicillin alone, while cellulitis may require broader-spectrum antibiotics to cover Staphylococcus aureus, including MRSA in some settings.