Can melanoma cause rash that looks like allergy? and can melanoma cause iron and vitamin d deficiency?

Not Likely: Melanoma would rarely ever cause an allergy type rash unless it was very severe and at a late stage. It is usually found as an abnormal pigmented lesion on the body, in the mouth, or on the retina of the eye. You should get a skin exam to have the rash looked at. There are many other less scary causes for an allergy rash. Melanoma would rarely cause vitamin deficiencies, unless late stage.

Not usually: A red rash would be an unusual appearance for melanoma. It usually looks like more discrete brown or black spots. Melanoma is typically not associated with any vitamin deficiencies.

Not usually: This is not a typical symptom. But best to bring it to the attention of your dermatologist. Melanoma can cause iron deficiency anemia if it has created tumors in the GI tract that are bleeding. Melanoma does not cause vit d def.