Archive | dermatology RSS feed for this section
Black flies, also known as buffalo gnats or turkey gnats, are blood-feeding insects in the insect family simuliidae. Immature black flies breed in fast-flowing water, from which the adults emerge in great swarms (usually) in spring or early summer. Black flies are notorious nuisance pests in certain parts of the world and are vectors of the agent of onchocerciasis in tropical areas. Nuisance biting alone can be serious, even fatal, with many reports of livestock and poultry deaths due to black fly biting.1, 2, 3 Outbreaks were a major problem in the southern United States during the early 20th century1 but disappeared until recently. This reemergence may be due to the elimination of harsh pesticides and the cleaning up of creeks and rivers.

Black fly bite reactions include papules, erythematous wheals, indurations, or extensive swelling of the affected area.4 In addition, adenopathy (black fly stiff neck) may occur from bites on the face, neck, and scalp.2 There are many reports of reactions to black fly biting in the northern United States and other parts of the world,2,5, 6, 7 but none from the southern United States, where black flies have typically not been a problem. Here we carefully document the timeline of bites and subsequent development of cutaneous lesions in an entomologist who was investigating a black fly outbreak along the Pearl River in central Mississippi during the spring of 2018.

Methods
The entomologist bitten by black flies was examined by the second author and bite reactions were described and photographed over the following 72 hours. Samples of the offending insect were collected and identified as Simuliim meridionale.

Results
From March 26 to April 2, at least 10 black fly bites were noted on the patient's arms, neck, and face. Bite reactions sometimes developed into large indurations by 48 hours (Figure 1). Two bites on the neck were carefully followed for 48 hours (Figure 2). At first, there was nothing but erythema and a small hemorrhagic center. Four hours later, lesions developed into a central wheal with surrounding erythema. The diagnosis was papular urticaria, presumably resulting from hypersensitivity to black fly salivary proteins. A raised urticarial papule developed at each bite site with surrounding erythema that itched intensely. Over the course of 24 hours, the urticarial lesions resolved, leaving only an erythematous flattened lesion. By 48 hours, the lesions had completely faded.

Development and Resolution of Cutaneous Lesions Caused by Black Fly Bites (Diptera: Simuliidae)

Black flies, also known as buffalo gnats or turkey gnats, are blood-feeding insects in the insect family simuliidae. Immature black flies breed in fast-flowing water, from which the adults emerge in great swarms (usually) in spring or early summer. Black flies are notorious nuisance pests in certain parts of the world and are vectors of […]

Read more

Adult-Onset Still’s Disease: A Classic Presentation of a Rare Illness

Adult-onset Still’s disease is a rare inflammatory disorder of unclear etiology. Here, we highlight a classic presentation of this disorder. Case Description A 30-year-old woman presented with a 1-month history of daily fevers, myalgias, 7.5-kg unintentional weight loss, and a 2-week history of diffuse skin rash. Her medical history was notable for Hashimoto’s thyroiditis, and […]

Read more
Strongyloides stercoralis larvae on bronchoalveolar lavage.

Strongyloides Hyperinfection

A 37-year-old male from Honduras with a history of brainstem glioblastoma treated with radiation, bevacizumab, temozolomide, and dexamethasone presented with sudden onset of dyspnea, pleuritic chest pain, and hoarseness. He also complained of a pruritic abdominal rash and painful swallowing. Physical examination revealed a temperature of 36.9°C; expiratory wheezing; and maculopapular rash on the chest, […]

Read more
Erythematous plaques with thick, micaceous scale on the extensor lower leg of a man with plaque psoriasis.

Psoriasis and Psoriatic Spectrum Disease: A Primer for the Primary Care Physician

Psoriasis is a chronic, immune-mediated disorder with cutaneous, articular, and systemic manifestations that are associated with significant morbidity.1 The burden of disease is directly related to its prevalence, which ranges from 0.5%-11.4% in adults and 0%-1.4% in children worldwide.2 In the United States alone, approximately 7.4 million individuals have psoriasis,3 and both the incidence and prevalence of psoriasis […]

Read more
Thinning of the hair in the frontoparietal scalp was due to androgenic alopecia.

At the Root: Cutaneous Langerhans Cell Histiocytosis

Hair loss is of deep concern to patients, mainly because of its effect on appearance. On rare occasions, however, areas of balding can signal malignancy. A 33-year-old woman was referred to our dermatology clinic because of a 15-year history of scalp eruption accompanied by intense itching and progressive hair loss. Previously, she was diagnosed with […]

Read more
(A) Skin impairment. Papulonodular skin lesions on the tip of the nose, from 3 to 10 mm, characteristic of sarcoidosis: firm, nonedematous, noninflammatory, nonpainful, nonpruriginous, with predominant facial involvement. (B) Endoscopic view (right nasal fossa) showing a major mucosae thickening. (C) Numerous uniform circumscribed nests of non-caseating granulomata which are characterized by the paucicity of lymphocytes and absence of necrosis.

Skin and Nasal Involvement: Look for Sarcoidosis!

  Sarcoidosis is a systemic, noncaseating, granulomatous disease affecting young adults between the ages of 25 and 40 years, most often of Black origin (35.5/100,000 vs 10.9 in the White population). Although the lower respiratory tract is affected in 90% of cases, ear, nose, and throat locations are very uncommon, with a prevalence varying between […]

Read more
UA-42320404-1