Infectious Diseases Case of the Month #10

A 76 y.o. white female was admitted to the hospital because of a blistering cellulitis of her right hand after undergoing carpal tunnel surgery the day before.

Within hours of her outpatient surgery the preceding day she had noted the onset of swelling beneath her surgical dressing and had experienced intense pruritus. When the dressing was removed by her surgeon on the day of admission to the hospital, there was obvious swelling and erythema of the palmar hand and distal forearm with large bullae and vesicles (see photos at left). The process extended to the dorsal interdigital webspace between the first and second fingers but otherwise largely spared the dorsum of the hand. The involved area was painful and pruritic, but the patient did not feel ill generally and was afebrile.

She had previously been in good health. Her past medical history was notable for breast cancer and hypertension. She was fond of seafood and visiting her Asian born grandchildren in Kansas City. Approximately three months prior to her current admission she had experienced a similar episode of rapid onset swelling and erythema after surgery to release a trigger thumb on the same hand. On that occasion her problem did not respond to outpatient cephalexin, then clindamycin. In the hospital she was treated with parenteral ceftriaxone and there was eventual resolution. Wound and blood cultures were negative.

Laboratory evaluation of the second (current) episode included WBC 9.7, Hgb 15.7, and Plts 257. Aspirate of fluid from the large bullae on her palm and two blood cultures were submitted to the microbiology lab before she was begun on IV antibiotics.

       
What is the most likely source of this patient's post-operative cellulits?
   
     
Diagnosis: None of the Above--Contact Dermatitis
   


This patient most likely had severe contact dermatitis secondary to povidone-iodine pre-operative skin preparation.

The stereotypical rapid onset of swelling and erythema on both occasions and the absence of significant systemic toxicity argued for contact dermatitis as the etiology of this patient's cellulitis. The fact that the second episode was more severe than the first was also consistent with this etiology as repeated exposure to a sensitizing agent would be likely to result in progressively worse signs and symptoms. Further evidence was negative blood and wound/bulla cultures on both occasions. The patient showed marked improvement when she was treated with systemic corticosteroids.

On both occasions the patient's hand was prepared for surgery by application of povidone-iodine skin degerming agents. On the first occasion the agent used was povidone-iodine "paint"; on the second, Prevail, a combination povidone-iodine/alcohol product. Use of preoperative antiseptics for skin preparation is a very important step in attempting to prevent surgical site infections. Contact dermatitis is a rare complication of the use of such agents.

Numerous topical medications have been reported to cause contact dermatitis. Some of the more common reported are lanolin, neomycin, para-aminobenzoic acid (PABA), local anesthetics, topical corticosteroids, and topical NSAIDS. Skin biopsy and/or patch testing can help confirm the diagnosis.

The various bacteria in the list in the vignette on the previous page (see original format) are all potential causes of cellulitis. Bacterial cellulitis is typically characterized by significantly more systemic toxicity than was evident in the case described. Two of the less common causes of cellulitis in the list are Vibrio vulnificus and Clostridium septicum. Vibrio vulnificus infection is associated with shellfish ingestion and saltwater exposure. In certain hosts it can cause fulminating illness. Clostridium septicum infection can cause crepitant cellulitis. It is more classically associated with bacteremic illness associated with colon cancer or hematologic malignancy where it can cause devastating illness with associated myonecrosis.


Ref: Vandergriff, T.W., et al, Irritant contact dermatitis from exposure to povidone-iodine may resemble toxic epidermal necrolysis, Dermatology Online Journal, 12(7):12


 

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