A longstanding super itchy rash on arm

M has a super itchy rash on her arm for some years.  She scratches almost all the time.  Rarely, the rash appeared to have "vanished", only to return with a vengeance some days afterwards.  She tried moisturizing but it didn't improve.

You can clearly appreciate the presence of many criss-crossing deep lines running across a large island of brown.  There are also a few reddish bumps which seem to have been recently scratched.  This is the classical appearance of chronic eczema; a specific name given to this rash with such deep perpendicular lines is lichen simplex chronicus.  This is an extremely itchy form of localised eczema.  In fact, scratching it is almost always a pleasurable experience (i think some people deliberately scratch to temporarily relieve stressful moments)!  This type of eczema will not go away with just moisturizing; one needs to see a doctor for some powerful steroid ointment to bring it down!

Sudden burning rash on back

T is a colleague's dad who complains of a sudden onset of a hot painful rash on his back.

Look closely and you can see many little bubbles, sitting on top of an island of pink-red.  This appearance is quite classical of herpes simplex infection.  The virus causing it is probably already existing on the skin, but it has "decided" to "activate" causing a localized infection.  See a doctor quickly to get a short course of antiviral medicine.  In the meantime, apply an antiseptic cream or gel to prevent bacteria from complicating things further!  This usually heals well.

One-sided acute rash on face

H complains of a blistering rash that affected only one side of his face. It resolved in about a week.

Notice a few things about this rash - it occurs on one specific area, not crossing the midline; the rash appears as separate islands; each island comprises of small blisters (some broken from scratching). This is shingles, or "snake" as what the older generation would say. It is due to the reactivation of the chickenpox virus due to some acute illness (which transiently lowers the body immune system so that the virus takes the opportunity to ''reactivate"), but sometimes it can occur spontaneously. The reactivated virus can run along any nerve root on one side of the body (in this case, it's along the mandibular division of the left trigeminal nerve). The appropriate treatment would be a course of oral anti-viral medication. Now, the skin can also heal without this medication, but the medication helps to hasten recovery! One should also keep the skin clean so as to reduce the chance of a bacterial super-infection. Some older folks can get a bothersome pain on the affected area after healing of the rash; they will need to see a doctor for some special nerve medication to control it...

Spontaneous expanding painful ulcer

N is a young girl with a painful spontaneous ulcer on her leg which enlarged quickly to 2.5cm in diameter over 3 weeks.

Ulcers can develop for many reasons - external injury and pressure (obviously), failure to sense pain (hence suffering repeated injury - usually in diabetics), blood vessel disease (eg varicose veins, blood vessel inflammation and/or obstruction) etc. The spontaneously-occurring ulcer you see here, however, is different from these. It expands very quickly, has a boggy edge and is painful. It is important to see a dermatologist ASAP to evaluate the cause as it looks like either a blood vessel inflammatory disease (which can be either on its own or involve internal organs too), or an uncommon 'skin-eating' disease called pyoderma gangrenosum (which also can be either on its own or related to an internal disease). Concomitant infection with bacteria should also be excluded and treated.

Spontaneous Bruises in an Elderly

My friend's mum was shocked to see bruises appearing on her arm one day. She didn't recall any injury.

In old people, skin dryness is very common (it's so dry that wrinkles have formed; see picture). It causes itch which leads to scratching. Again in old people, there is poor collagen support for the blood vessels, hence these superficial vessels break easily with very minor trauma such as scratching. The bruises that form will go away on their own with time, so there is no need for alarm. This is why it is important for old people to moisturize their skins regularly!

Got a problem with your skin?

Hi folks

I am a dermatologist practising in a tertiary institution in Singapore, and I see the full range of cases - medical, surgical and cosmetic skin problems of all ages. I also do a great deal of teaching and research.

This blog serves the following purposes:
1. let people ask about their problem skins and we work out some solution
2. let others learn from your problem skin and how it was dealt with

So, what are you waiting for? Post me your problem at theproblemskin@gmail.com (must come with pictures, okay!) and see if it may be eradicated DIY, or that you do need to see a doc! Don't be shy... what have you got to lose??

Dr Skin Solution

PS. By mailing me your picture, you automatically consent to your picture being used as any form of teaching and publicity material.