Contagious disease and Scarlatina

Contagious disease noun - Any disease easily transmitted by contact.

Scarlatina and contagious disease are semantically related. In some cases you can replace term "Scarlatina" with "Contagious disease", this terms are similar.

Scarlatina noun - An acute communicable disease (usually in children) characterized by fever and a red rash.

Contagious disease and scarlatina are semantically related. You can use "Contagious disease" instead a noun "Scarlatina".