Solitary plaque on dorsal hand - Clinical Advisor

Solitary plaque on dorsal hand


  • August 2014 Dermatology CME/CE


Audrey Chan, MD

A 29-year-old white male presented to the dermatology clinic with an eruption on the left hand that had been present for 1 week. He complained of tenderness to palpation. A review of systems was negative for fever, chills, or arthralgias.

The patient was otherwise healthy and reported being an avid hunter and fisher. The only medication he was using was clindamycin, which had been started by his primary-care physician for this lesion.

Physical examination of the patient was notable for a solitary erythematous edematous plaque with central clearing on the right dorsal hand with sparing of the distal digits.

This Clinical Advisor CME activity consists of 3 articles.To obtain credit, you must also read Patchy hair loss on 
a bearded chinand Long-term scaly skin
. Then take the post-test here.

Erysipeloid is a cutaneous bacterial infection caused by Erysipelothrix rhusiopathiae, formerly known as Erysipelothrix insidiosa.1E. rhusiopathiae is a rod-shaped, Gram-positive bacteria.1 It is non-motile, nonsporulating, and found on dead matter of animal origin.1,2 Erysipeloid is most commonly transmitted by pigs;...

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Erysipeloid is a cutaneous bacterial infection caused by Erysipelothrix rhusiopathiae, formerly known as Erysipelothrix insidiosa.1

E. rhusiopathiae is a rod-shaped, Gram-positive bacteria.1 It is non-motile, nonsporulating, and found on dead matter of animal origin.1,2 Erysipeloid is most commonly transmitted by pigs; a large number of these animals are carriers of E. rhusiopathiae despite being otherwise healthy.1,2

The organism can also be transmitted by fowl (chickens, turkeys, and ducks) and emus.1 E. rhusiopathiae may also be present in the slime of saltwater fish (e.g., scorpion fish) or other shellfish (e.g., crabs and lobsters).2

For that reason, erysipeloid is most commonly contracted by individuals whose occupations involve exposure to contaminated meat and fish, and the incidence is high among commercial fishers along the Atlantic seacoast.2

The infection also occurs commonly among veterinarians and employees in the meat-packing industry.2 Erysipeloid has also been reported in “animal breeders, furriers, housewives, cooks, and grocers.”1 Nonoccupational cases are very rare, thus erysipeloid occurs most commonly in adults with only rare reports in children.1 The incidence of erysipeloid is declining due to technological advances in the food industry.1

Clinically, erysipeloid is subdivided into localized and generalized forms. In the localized form, a nonsuppurative cellulitis is noted.3 The first symptom is pain at the site of inoculation, which is followed by erythema and edema.2

Distinctive features of erysipeloid are sharp demarcation, often with polygonal patches of bluish erythema.2 Occasionally, hemorrhagic vesicles may be seen.

The classic description of erysipeloid is that of an erythematous plaque on the dorsal hand with involvement of the finger webs but sparing of the distal digits.3

A central clearing may be noted as the erythema slowly spreads to produce a sharply defined, slightly elevated border as the central portion fades away.2 Rarely, if the finger does become involved, the digit may become so edematous that movement becomes difficult.2

Erysipeloid may also be characterized by migration with new purplish-red macules or patches at nearby areas. Constitutional symptoms such as fever and chills rarely occur in localized erysipeloid.3 Localized erysipeloid typically is self-limited and resolves without desquamation or suppuration.2,3

In contrast to localized erysipeloid, generalized erysipeloid is usually accompanied by constitutional complaints including fever and arthralgias.3 As the name suggests, the lesions in generalized erysipeloid are widespread. The appearance of individual lesions can vary widely from perifollicular papules to erythematous plaques to macular purpura.3 Some lesions may become necrotic.3 Rarely, endocarditis, septic arthritis, and cerebral and other visceral abscesses may complicate cases of generalized erysipeloid.

The diagnosis of erysipeloid is made on clinical grounds based on the appearance of the eruption and the patient’s history of exposure to meat or seafood. E. rhusiopathiae is difficult to culture, but polymerase chain reaction-based assays are available and may have higher sensitivity.3 If culture is attempted, it is best grown on media fortified with serum at room temperature.2

The differential diagnosis includes cellulitis, erysipelas, spider bites,and fixed drug eruptions.3 Histologically, cellulitis and erysipelas may be difficult to distinguish from erysipeloid; however, certain clinical features can be helpful in that regard. Cellulitis is a bacterial infection of the deep dermis and subcutaneous tissue with resultant erythema, swelling, warmth, and tenderness.3

The most common causes of cellulitis are group A streptococci or Staphylococcus aureus. In persons with diabetes, however, a mixture of Gram-positive cocci and Gram-negative organisms is not uncommon. Risk factors for cellulitis include a break in the skin barrier, lymphedema, alcoholism, diabetes mellitus, intravenous (IV) drug abuse, and peripheral vascular disease.3;Unlike in erysipeloid, in cellulitis the borders are ill-defined and nonpalpable.3

Erysipelas is a superficial cellulitis with lymphatic involvement.3 The demographic population affected by erysipeloid is very different from that affected by erysipelas. Whereas erysipeloid is usually contracted as an occupational exposure, and thus more likely to be seen in healthy adults, erysipelas affects the very young, the elderly, the debilitated, and those with edema or chronic cutaneous ulcers.3

The most common locations of erysipelas are the lower extremity followed by the face.3 Unlike localized erysipeloid, which often lacks constitutional symptoms, erysipelas is almost always accompanied by abrupt onset of fever, chills, and malaise.3

Like erysipeloid, erysipelas is also well demarcated; however, regional lymphadenopathy is usually present in erysipelas but not in erysipeloid. Also in contrast to erysipeloid, erysipelas tends to resolve with desquamation and postinflammatory pigmentary change.3

Widow spider (Lactrodectus) bites may also be accompanied by acute pain and edema as in erysipeloid; however, with Lactrodectus bites, extracutaneous manifestations are often prominent, including painful muscle spasms and acute surgical abdomen.3 Patients may or may not recall the incident spider bite.

Fixed drug eruption (FDE) is usually not characterized by central clearing and leaves robust postinflammatory hyperpigmentation. The three most common causes of FDE are trimethoprim-sulfamethoxazole, nonsteroidal anti-inflammatory drugs, and tetracyclines.

FDE tends to recur in the same locations with each re-exposure to the culprit medication. A biopsy is usually helpful in distinguishing erysipeloid from spider bites and FDEs.

Even without treatment, most localized episodes of erysipeloid are self-limited and resolve in about 3 weeks.2,3 Penicillin is the treatment of choice at a dose of 1 g per day for 5 to 10 days.2,3 Alternatively, ampicillin 500 mg 4 times a day for 5 to 10 days may be prescribed.2

Erythromycin, tetracyclines, ciprofloxacin, clindamycin, or imipenem may be used for patients allergic to penicillin.2,3 After erysipeloid appears to have resolved, the infection may recur in an adjacent area or in the previously affected area, requiring another course of treatment.2

Systemic erysipeloid is treated with IV penicillin 12 to 20 million units per day for up to 6 weeks.2 Prevention is key. Patients should be advised to use gloves during exposure to fish or meat.3

Because our patient had already been started on clindamycin by his primary-care physician, that treatment was continued, with resolution of the infection. The patient was advised on the use of gloves when hunting and fishing.

Audrey Chan, MD, is a pediatric dermatology fellow at Texas Children’s Hospital in Houston.

This Clinical Advisor CME activity consists of 3 articles. To obtain credit, you must also read Patchy hair loss on 
a bearded chin and Long-term scaly skin
. Then take the post-test here.


  1. Veraldi S, Girgenti V, Gianotti R. Erysipeloid. Clin Exp Dermatol. 2009(34)8:e605-e607.
  2. James WD, Berger TG, Elston DM. . 11th ed. Philadelphia, Pa.: Saunders Elsevier, 2011: 259-260.
  3. Bolognia JL, Jorizzo JL, Rapini RP. Dermatology. 3rd ed. St. Louis, Mo.: Elsevier-Mosby; 2008:chap. 74.
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