Case report: Cellulitis and underlying fungal infection

Subtle clues can often aid diagnosis in patients with skin conditions, writes Dr Nigel Stollery

Figure 1: Swollen, inflamed left lower leg, ankle and foot (Image: Dr Nigel Stollery)
Figure 1: Swollen, inflamed left lower leg, ankle and foot (Image: Dr Nigel Stollery)
This 65-year-old woman, who had recently moved to the area, presented with a swollen inflamed left lower leg, ankle and foot (figure 1). She reported that this had been the case for a number of months. 

She had seen several GPs, who had diagnosed cellulitis and treated her with courses of oral antibiotics, such as flucloxacillin and doxycycline

There had been a reduction in the pain and redness with the antibiotics, but this had only been temporary and the symptoms had recurred every few weeks. 

More recently, she had developed some localised ulceration on the dorsum of the foot. These ulcers had discharged pus at times and were quite painful. 

The patient had never smoked, and had no history of cardiac problems, diabetes or asthma. She did have varicosities in both legs, but the left side was no worse than the right and the varicosities had remained unchanged for a number of years. 

The right foot had never been affected and before the onset of this, there had been no history of any skin problems, such as eczema or dermatitis. 

There was also no history of peripheral oedema in the feet and ankles before these recent episodes of cellulitis. 

She had a history of hypertension and her medication included an ACE inhibitor and bendroflumethiazide

At the time of the initial consultation, the foot appeared infected, the skin was red and warm, and the patient had a mild pyrexia of 37.4°C. 

A swab was taken from the larger ulcer and she was restarted on flucloxacillin 500mg four times a day with paracetamol

A few days later, the patient was reviewed and there appeared to be an improvement. She was apyrexial and the ulceration appeared drier and less painful. 

The swab results indicated Staphylococcus aureus with sensitivity to flucloxacillin.

Despite the antibiotics, the skin continued to look red and closer inspection revealed scaling, which was not present on the right foot. The toe webs were normal, as was the plantar surface of the feet. 

The nails were not normal, however, with dystrophy and changes suggestive of a fungal infection. This was particularly noticeable in the left great toenail. The patient reported that this had been present for a number of years but caused her no problems. She was seen regularly by a chiropodist.

Nail clippings and skin scrapings were taken and she was advised to complete the course of antibiotics. Mycology was positive for fungal elements, in both the nail clippings and the skin scrapings, raising suspicion of an underlying fungal infection in the skin. 

Her liver function was checked and she was commenced on a course of oral terbinafine 250mg daily. Over the following weeks, there was a marked improvement in the limb, with decreased redness, complete healing of the ulcers and a reduction in the superficial scale. Eventually, the limb returned to normal and there have been no further episodes of cellulitis. 

The ulceration, pyrexia, swab result and response to oral antibiotics suggest there had been recurrent episodes of a bacterial cellulitis, but the underlying problem was the fungal infection, which created a portal of entry for the bacteria. Without addressing this, the cellulitis continued to recur. 

This is a good example of where subtle clues can help to make an accurate diagnosis. In this case, the unilateral presentation, scale and chronic onychomycosis were very important and helped to achieve a long-term cure. 

  • Dr Nigel Stollery is a GPSI in dermatology, Kibworth, Leicestershire

Competing interests: None declared

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