Stream 1 General Dermatology - Infestations and Bites

Topics to be covered in the Certificate Course.

Scabies
Papular urticaria
Swimmer's itch and Seabather's eruption

Scabies

You should spend some time in this section because at some stage in your life you are going to either get scabies or pubic lice from a close encounter of the sexual kind or your children are going to come home with nits in their hair. Scabies is the king of infestations. If you get two people in a family itchy at the same time it is scabies until proven otherwise. You diagnose scabies on the basis of the distribution of the rash and hopefully finding a small scabetic burrow in the skin. Sometimes the only way that you can convince people that they have scabies is to deroof a burrow and show the scabetic mite under a microscope on a slide. If you have a dermatoscope then this is an excellent way to show the burrow.

Question

How will scabies present to you?

Answer

A patient will come in and they will be complaining of itch. They will say that it is all over but if you ask them if it involves the face and head they will say no. When you examine them you will find the skin is excoriated and scratched and it can be quite difficult to find a burrow. If you are looking for a burrow the main areas to look are as follows:

Ø      The web spaces between the fingers.

Ø      The wrist especially the ulna surface.

Ø      Around the point of the elbow.

Ø      The anterior axillary fold.

Ø      The periumbilical area.

Ø      And also the genital skin especially in males.

Look for post scabetic nodules. These are areas of hypersensitivity to the scabies mite in the skin and they are particularly seen on scrotal skin and in the axillae.