Here's an excerpt from FAB's ringworm info.
What does a cat with ringworm look like?
'The appearance of cats with ringworm is very variable. Some cats have severe skin disease while other cats have only very minor lesions or no lesions at all and look completely normal. Typical skin lesions are discrete, roughly circular areas of hair loss, particularly on the head, ears or extremities of the paws. The hairs surrounding affected areas appear broken. The affected skin is often scaly and may look inflamed. However, ringworm can look very similar to many other feline skin diseases, including some of the clinical manifestations of flea allergy dermatitis, and may present as symmetrical alopecia or even feline acne. Some loss of hair is usually involved, but the amount of inflammation, scaling and itchiness (pruritus) can be very variable. In very unusual cases cats may appear just to have an ear infection or infection of the claws. '
