Crusted scabies
Crusted scabies (which is also sometimes referred to as Norwegian scabies) is a more severe form of scabies that affects people who have a weakened immune system.
People who may have a weakened immune system include:
- the very young,
- the very old,
- people with a condition that affects their immune system, such as HIV,
- people who are taking steroids to treat other medical conditions, and
- people undergoing chemotherapy.
Research has found that a healthy immune system seems to interrupt the reproductive cycle of the scabies mite. For example, most people who are affected by the condition will only have between 5-15 mites on their body at any one time.
However, if your immune system is weakened, the number of scabies mites can increase dramatically. People with crusted scabies can have literally millions of scabies mites in their body at any one time. The increase in the number of mites causes the appearances of thick, warty crusts to appear on the skin.
Due to the high number of scabies mite, crusted scabies is highly contagious. However, transmission from someone with crusted mites will only lead to the normal type of scabies in those with a healthy immune system. Even minimal physical contact with a person with crusted scabies, or their bed linen, or clothes can lead to infection.
As strict controls are required to limit the spread of crusted scabies, the condition may need to be treated in hospital.
Crusted scabies can be treated by using insecticide creams, or a medicine called ivermectin, which is taken orally (as a tablet). Ivermectin kills the mites by stopping their nervous system from working.
Secondary infection
Excessive itching of the skin can break the surface of the skin and make it vulnerable to a bacterial infection, such as impetigo (a highly contagious bacterial infection). Antibiotics may be required to control any secondary infection.
Scabies has been known to worsen other pre-existing skin conditions, such as eczema. However, if you have another skin condition, it should settle down once the scabies has been successfully treated.
