The Physician and Sportsmedicine
Menubar About Us Advertiser Services CME Resource Center Personal Health Journal Home

Rash After ACL Reconstruction

Asking the Right Questions

Andrew H. Smith, MD; Bernard R. Bach, Jr, MD


A 40-year-old recreational athlete injured his left knee on a "moon bouncer" at his child's birthday party. Before the injury, he regularly went hiking and downhill skiing and played basketball and tennis. Because the injury caused persistent symptoms of knee instability, he elected to undergo an anterior cruciate ligament (ACL) reconstruction using allograft. At the time of surgery, the patient's skin examination was unremarkable, and no surgical complications were noted. The patient went home on the day of surgery.

The patient returned 3 days after surgery, reporting severe itching and the development of a rash on his legs (figure 1). The rash originated distally at both ankles, and then spread proximally toward the knees over the course of 2 days. Examination revealed an erythematous rash with linear streaking and multiple patches of vesicles.

What is your diagnosis? What conditions should be included in the differential diagnosis? What additional information from the history do you require?


The differential diagnosis included host-versus-graft reaction, drug reaction, and contact dermatitis. Additional questioning revealed that the patient went on a camping trip in an area with abundant endemic poison ivy and poison oak a few days before surgery. The diagnosis was plant contact dermatitis (figure 2). Supporting the diagnosis were the facts that the rash was present on the nonoperative leg, and that his daughter—who accompanied him on the camping trip—developed the same rash.

The patient was evaluated at 1- to 2-week intervals until 6 weeks postsurgery. Skin examination at that time showed no evidence of abnormality; the rash had completely resolved.

Toxicodendron Contact Dermatitis

The rash was caused by contact with urushiol, a resinous oil present on plants of the Anacardiaceae (cashew) family, Toxicodendron genus. The resin can cause severe skin irritation. Poison oak, poison ivy, and poison sumac are all members of the Toxicodendron genus.

In North America, more cases of contact dermatitis are caused by exposure to poison ivy, poison oak, or poison sumac than all other causes of contact dermatitis combined. Each year approximately 10 to 50 million Americans seek medical attention after contact with these plants. Poison ivy, oak, and sumac are found in all of the continental United States. Poison ivy and sumac are typically found in the eastern and central regions; poison oak is more common in western states.1,2

After contact, urushiol quickly penetrates the skin. If the skin is not washed within 30 minutes of contact, little can be done to prevent rash formation in the sensitized individual. The rash typically appears within 48 hours after contact, but, occasionally, it may not develop for 3 to 10 days. The interval between contact and rash formation is variable, depending on skin thickness, length of contact, and prior exposure.

The classic rash begins as an erythematous, pruritic outbreak. Characteristic linear streaks form along the lines of contact where the plant dragged across the skin. Vesicles erupt as the rash develops, and the patient experiences severe itching. The rash is not contagious, because the fluid in the blisters does not contain the urushiol; therefore, ruptured blisters do not spread the rash.

The resin can remain adherent to clothes or pets. Unless removed, residual plant resin on clothes is still capable of causing the rash, even up to a month after the initial contact. Urushiol can also be suspended in the smoke from the burning of poison ivy leaves, roots, or vines and can produce the rash or cause serious irritation to bronchial passages and lungs.1,2

Other Postoperative Possibilities

Rashes are described in graft-versus-host reactions after bone marrow transplantation.3 Unlike bone marrow transplants, fresh frozen nonirradiated allografts have very low immunogenicity and do not require tissue typing. Graft-versus-host reactions are extremely rare in ligament transplantation for ACL reconstruction. The reactions are subclinical and are not associated with rash.

Drug reactions in the postoperative period are rare, but they do occur. Up to 3% of inpatients develop drug-related rashes, most often associated with antibiotics used for prophylaxis or blood products.4,5 Antibiotic-related rashes are usually generalized and have a maculopapular pattern. Anesthetics and postoperative analgesics can also be responsible for rashes.5 Certain drug-related rashes associated with anticoagulants and diuretics usually localize to the lower leg and ankles, are purpuric, and do not form linear streaks or vesicles.

Contact dermatitis caused by antiseptic skin preparation before surgery is infrequent, but not unknown with 10% povidone-iodine solution.6,7 Our patient's skin was prepared before surgery with a commonly used combination of 72.5% isopropyl alcohol and 8.3% povidone iodine.

Because rash developed on the contralateral, unprepped leg and on a family member, host-versus-graft reaction, drug reaction, and surgical prep were unlikely causes of the rash in this case.

Contact Dermatitis Treatment and Prevention

The best way to prevent rash formation is to become familiar with the appearance of these irritating plants and avoid contact (figures 3 through 5). If contact cannot be avoided, then clothing or barrier lotions can be used to limit exposure. If contact occurs, thoroughly washing with soap and water as soon as possible may help remove the urushiol.

Mild cases can be treated with oral antihistamines and a topical lotion, such as calamine. Topical antihistamines should be avoided, because they may themselves potentiate an allergic contact dermatitis. Moderate cases may require potent (class 1 or 2) topical corticosteroids. More severe cases may require oral, intramuscular, or intravenous corticosteroid administration. Cool compresses applied in a wet-to-dry fashion aid in the resolution of vesicles and provide symptomatic relief. Healing generally takes 10 days to 3 weeks. Scarring is rare and is usually associated with excoriation rather than the rash itself.

Changing Expectations

This case emphasizes the importance of obtaining additional history and physical exam data when the clinical situation varies from the expected scenario.


  1. McGovern TW, Barkley TM: Botanical dermatology. Int J Dermatol 192021;37(5):321-334
  2. Anderson TE: Poison Ivy, Oak & Sumac. Schaumburg, IL, American Academy of Dermatology, 1999. Available at Accessed September 10, 2021
  3. Mascaro JM, Rozman C, Palou J, et al: Acute and chronic graft-vs-host reaction in skin: report of two cases. Br J Dermatol 120210;102(4):461-466
  4. Bigby M, Stern RS, Arndt KA: Allergic cutaneous reactions to drugs. Prim Care 120219;16(3):713-727
  5. Hunziker T, Kunzi UP, Braunschweig S, et al: Comprehensive hospital drug monitoring (CHDM): adverse skin reactions, a 20-year survey. Allergy 1997;52(4):388-393
  6. Iijima S, Kuramochi M: Investigation of irritant skin reaction by 10% povidone-iodine solution after surgery. Dermatology 2021;204(suppl 1):103-108
  7. Reichert-Penetrat S, Barbaud A, Penetrat E, et al: Allergic contact dermatitis from surgical paints. Contact Dermatitis 2021;45(2):116-117

Dr Smith is a fellow and Dr Bach is a professor and director in the division of sports medicine in the department of orthopedic surgery at Rush University Medical Center in Chicago. Address correspondence to Bernard R. Bach, Jr, MD, Rush University Medical Center, 1725 W Harrison St, Suite 1063, Chicago, IL 60612; e-mail to [email protected].

Disclosure information: Drs Smith and Bach disclose no significant relationship with any manufacturer of any commercial product mentioned in this article. No drug is mentioned in this article for an unlabeled use.