Conditions Involving Insects or Ticks

Click through the slides to view cases of conditions transmitted by insects or ticks featured in the Consultant archives. Each slide links to the full case report for more details.

A 67-year-old, previously healthy man presented with a pruritic eruption on his trunk, legs, and arms. The skin manifestations had appeared 1 week after he had come into contact with animal feces in stagnant water while inspecting a house. As the eruption evolved, the pruritus worsened, and the patient developed an intense burning sensation. Slowly advancing lesions appeared on the skin. 

The patient had gone to an urgent care center and had been prescribed oral fluconazole, which had minimally improved his rash. Nevertheless, the pruritus remained severe, and he had attempted to self-medicate with diphenhydramine and topical econazole cream.

At presentation, the patient denied blisters, chills, fevers, joint aches, new medications, new personal care products, or recent infections. The patient’s spouse did not have any similar symptoms. Sweating seemed to exacerbate the patient’s symptoms.

For the full case report, click here.

A 62-year-old man with a history of hypertension, hyperlipidemia, benign prostatic hyperplasia, and gastroesophageal reflux disease presented with a 3-week history of swelling on the dorsum of his right hand that was painful to touch. His medications included amlodipine, lovastatin, finasteride, esomeprazole, and doxazosin. His allergy status was unknown. The patient had recently immigrated to the United States from South America.

For the full case report, click here.

Human botfly infestation, also known as human cutaneous botfly myiasis, is relatively rare in the United States. The Dermatobia hominis larvae infest the skin and live out 3 self-limiting larval stages, causing pain and discomfort to the host. The typical presentation includes a cystic nodule with a well-defined central pore.¹ Although the botfly is indigenous to Mexico and Central and South America, cases of cutaneous botfly infestation have been reported in the United States and Japan in travelers who had visited endemic areas.^2,3

The life cycle of the human botfly begins with the female botfly laying her eggs on a blood-feeding insect, most commonly a mosquito or a tick.⁴ When the insect feeds on a warm-blooded mammal—commonly dogs, cattle, cats, horses, or in some cases, humans—the eggs hatch as a result of the warmth. The larvae then burrow into the host’s skin through the bite wound or a hair follicle and anchor into the subcutaneous layer by means of small spines on their exterior surface. Once anchored, the larvae mature and remain in the host for 5 to 12 weeks.⁵ As the larvae grow, a compressible and painful lesion develops on the surface of the skin. In the United States, the diagnosis of human botfly infection often is missed or is misdiagnosed as either superficial cellulitis, an infected sebaceous cyst, or an insect bite resulting in a skin lesion.⁶

For the full case report, click here.

A 58-year-old woman developed a painful red rash behind her left knee. She lived in a wooded area of Connecticut, which is moderately endemic for Lyme disease, but she had spent the day outside picking apples in a hyperendemic area of the state 8 days before the onset of her eruption. She was not aware of a tick bite.

Her rash had enlarged over 3 days and prompted a visit to her primary care physician. At that visit, she was afebrile and had no systemic complaints. Physical examination findings were unremarkable except for a slightly painful, erythematous, annular rash behind her left knee. 

For the full case report, click here.

A 51-year-old Filipino man presented for a screening colonoscopy. The patient denied any significant complaints including diarrhea, hematochezia, fever, chills, and weight changes. He reported having a good appetite. 

He had emigrated from the Philippines in his late teens, but he had served in the US Army for 25 years, including tours in Southeast Asia.

For the full case report, click here.

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