Book menuRASHES - Full extract 

 I was pleased to see Bjorn when he came into the surgery one Saturday morning. He is studying Engineering at a country TAFE college and I hadn't seen him for months.

" This is a bit embarrassing, doctor," he said. " I have got this itchy rash in my groin." He had a red rash around the top of his legs. It was slightly raised around its margins and it extended onto his scrotum, which looked rather weepy from scratching. Apparently, the rash appeared a few weeks earlier, just after he began training for basketball. " It stings a little when I sweat, " he said. " And it's getting worse."

The rash was quite typical of tinea, a fungal infection that commonly occurs in the groin area. I gave Bjorn a quick general examination and also checked his urine for sugar. Everything was normal. 

He was pleased to hear that the rash was nothing drastic, and that it would settle quickly with antifungal cream and some extra care in drying himself. He rang from college a fortnight later to tell me that the rash had almost gone. 

Rashes are really just collections of patches, blotches or spots. They are usually red, but some rashes can be purply or even brownish. They are very common and quite a challenge to sort out. There are several important distinguishing characteristics about any rash:- 

  • Is it generalized, or localized to one part of the body? 
  • Is it itchy? 
  • Is it flat, raised or blistery? 
  • What part of the body is affected? 
  • Is it just on the sun- exposed areas? 
  • Has the person recently been on medication, or currently  taking medication? 
  • Is the person sick, or looking unwell? 

It is not possible to advise on rashes over the phone. A thorough history and careful physical examination is necessary if a rash is going to be properly identified. 

Viral infections are probably the most common cause of a generalized rash. Although chickenpox, measles and rubella produce fairly typical rashes, the majority of viral infections cause a very non-specific rash. Because of the harmful effects of rubella on the developing foetus, anyone with suspected rubella is advised to avoid contact with women who might be in the early stages of pregnancy. 

Meningococcal septicemia is a life-threatening illness that is caused by a bacterial infection. It can present with a rash that looks like tiny purple bruises. The person is usually seriously ill and may have features of meningitis such as fever, headache, vomiting and neck stiffness. Although very uncommon, occasional outbreaks do occur and it tends to affect children and young adults. The condition is a medical emergency and requires immediate specialist care.

Bacterial infections can cause a number of skin rashes, as can fungal infections and thrush. Parasitic infections such as scabies can produce an itchy rash, which may not be easy to identify initially. 

Allergies often cause a generalized and itchy rash, and in places the skin may be raised in welts. They may occur after medication like penicillin, but virtually any medication can cause a rash in someone who is susceptible. Allergic rashes can also occur in response to foods, chemicals, detergents, and even shrubs in the garden. 

Skin conditions such as eczema and psoriasis cause specific types of rashes. Often there is a history of previous skin problems, and the rashes may be localized to areas such as the elbows, knees or scalp. 

Perspiration rashes called intertrigo often occur under the breasts and in the groin area. Sometimes these rashes are made worse by an associated thrush or fungal infection. Some people develop heat rashes on the chest and limbs, especially in warm weather or with a fever. Blotchy rashes can also occur on the chest in response to stress or nervous tension. 

There is also a rather large " heaven-only-knows " category. Despite careful assessment, the precise cause of some rashes remains unclear. Presumably, some are due to viral infections and allergies. Usually these mystery rashes go away without treatment. However, if they persist or cause discomfort, referral to a skin specialist may be required. 

The treatment of any rash depends on the underlying cause. Every effort should be made to positively identify the cause of a rash. Many require no treatment at all. If itching is a problem, the doctor may prescribe various topical creams or ointments, as well as oral medications. There is also a variety of moisturizing and soothing preparations that can be applied to the skin if necessary. 

Health tips: 
* If you are on a new medication and a rash occurs, stop it and contact your doctor straight away to see whether the medication could be responsible. 

* If someone is very sick and develops a rash, seek urgent medical attention, in case a serious infection is present.


 Dr. Andrew Pattison: Common Consultations
North East Valley Division General Practice, Melbourne, Australia.   Disclaimer
  - Last modified: August 18, 2001