An Elderly Diabetic Patient with Necrotic Arachnidism

Elghblawi Ebtisam, MBBCh, MSc, PG Dip


Dermatology Nursing. 2010;22(3):39-42. 

In This Article

Abstract and Introduction


The brown recluse (Loxosceles) is one of 100,000 species of spiders worldwide and considered to be one of the most medically significant assemblies of spiders. Generally, brown recluse spider bites are asymptomatic; however, its bite can cause severe skin necrosis.


A 62-year-old Libyan woman with diabetes presented to the dermatology clinic with a necrotic brown lesion on the back of her right thigh. The lesion was noted after she felt a sting while sitting in a car. It was painful with a burning stinging sensation at the site of the bite, and was associated with a diffuse striking toxic redness (generalized posterior thigh exanthema) which expanded to the area alongside the bite and included edema and severe itching. The lesion was located on the posterior part of her right thigh (see Figure 1), measured approximately about 2 x 3 cm, with a central oozing necrotic ulceration at the base.

Figure 1.

Spider bite

There was no evidence of systemic distress and baseline investigations were unremarkable apart from a raised erythrocyte sedimentation rate (ESR) (40 mm/hr). Community-acquired methicillin-resistant staphylococcus aureus (MRSA) was excluded by negative pus culture. Based on the history and the typical appearance of the lesion, the diagnosis was thought to be brown recluse spider bite. The patient was treated with oral antibiotics: flucloxacillin capsules (Floxapen®) 500 mg four times a day for 2 weeks, with local Fucidin® after application of a local wet compressor (potassium permanganate 1/8000, twice a day), as the wound appeared to be wet and infected. She also received simple analgesics (pain control), non-sedative antihistamine HISTOP® 4 mg (long-acting chlorpheniramine tablet twice a day to alleviate scratching). In some cases where the ulcer can be extensive, steroids orally can be added to the antibiotics to combat any further necrosis and destruction which was not the case. She was advised to rest, apply ice locally, and to followup regularly. The lesion improved considerably (see Figure 2) and the pain and swelling subsided at week 1 followup.

Figure 2.

Spider bite after 1 week


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