Clustered erythematous macular to papular lesions, especially those that stop at clothing lines, are a frequent manifestation of insect bites. In this case, the lesions lacked a central punctum that is common in many insect bites, so the most likely culprit was bed bugs. It is likely that this patient’s friend inadvertently brought the bed bugs into the home in her luggage or packed belongings. Over time, they spread around the home, causing the patient’s bites and inflammation. When questioned, the patient noted that she could actually see bugs around the couch in her home.
The scientific name for bed bugs is Cimex lectularis. Bed bugs require a blood meal from a host to survive, but they do not remain attached to the human body. Instead, they live in nearby fabrics. Bed bugs are visible to the naked eye when they are in the open, although they usually remain along the seams of fabric, edges of bedding, or in cracks and crevices. Often the feces of bed bugs will collect and be seen as dark spots or streaks on bedding.1
Treatment hinges on the eradication of the bed bugs. The erythematous itching lesions will resolve spontaneously over 1 to 2 weeks. Topical corticosteroids, including hydrocortisone, can be used as necessary to control the itching. Oral antihistamines can also help with itching.
Eradication of all the bed bugs in the home can be difficult and warrant professional extermination services. Washing clothing in hot water of at least 140 °F will kill the insects. Freezing items below –4 °F for at least 2 hours is also effective but may not be possible with home freezers.
It’s worth noting that resistance to insecticides has developed, making chemical eradication difficult. An alternative extermination protocol involves heating an entire home to the required temperatures to eradicate the infestation.1
This patient noted that she had already thrown away the couch, clothes, and bedding where she had seen the insects and had sprayed her apartment with insecticide. She was counseled to contact a professional exterminator to further evaluate the home for any additional areas of infestation and treat if any bed bugs were still in the home. She was also counseled to use loratadine 10 mg/d orally and topical 1% hydrocortisone ointment, as needed, for the itching and inflammation.
Photo and text courtesy of Daniel Stulberg, MD, FAAFP, Professor and Chair, Department of Family and Community Medicine, Western Michigan University Homer Stryker, MD School of Medicine, Kalamazoo.