Erythema may occur at a dose of 2 Gy radiation or greater. Chronic
Chronic radiodermatitis occurs with chronic exposure to "sub-erythema" doses of ionizing radiation over a prolonged period, producing varying degrees of damage to the skin and its underlying parts after a variable latent period of several months to several decades. : 40   In the distant past this type of radiation reaction occurred most frequently in radiologists and radiographers who were constantly exposed to ionizing radiation, especially before the use of X-ray filters. : 40   Chronic radiodermatitis, squamous and
basal cell carcinomas may develop months to years after radiation exposure. : 130   Chronic radiodermatitis presents as atrophic indurated plaques, often whitish or yellowish, with telangiectasia, sometimes with hyperkeratosis. : 130

Other
Eosinophilic, polymorphic, and pruritic eruption associated with radiotherapy is a skin condition that occurs most often in women receiving cobalt radiotherapy for internal cancer. : 39–40 Radiation-induced erythema multiforme may occur when phenytoin is given prophylactically to neurosurgical patients who are receiving whole-brain therapy and systemic steroids. : 130

Delayed effects
Radiation acne is a cutaneous condition characterized by comedo-like papules occurring at sites of previous exposure to therapeutic ionizing radiation, skin lesions that begin to appear as the acute phase of radiation dermatitis begins to resolve. : 501 Radiation recall reactions occur months to years after radiation treatment, a reaction that follows recent administration of a chemotherapeutic agent and occurs with the prior radiation port, characterized by features of radiation dermatitis. Restated, radiation recall dermatitis is an inflammatory skin reaction that occurs in a previously irradiated body part following drug administration.
Takotsubo cardiomyopathy or Takotsubo syndrome (TTS), also known as stress cardiomyopathy, is a type of non-ischemic cardiomyopathy in which there is a sudden temporary weakening of the muscular portion of the heart. It usually appears after a significant stressor, either physical or emotional; when caused by the latter, the condition is sometimes called broken heart syndrome. Examples of physical stressors that can cause TTS are sepsis, shock, and pheochromocytoma, and emotional stressors include bereavement, divorce, or the loss of a job. Reviews suggest that of patients diagnosed with the condition, about 70–80% recently experienced a major stressor, including 41–50% with a physical stressor and 26–30% with an emotional stressor. TTS can also appear in patients who have not experienced major stressors.The pathophysiology is not well understood, but a sudden massive surge of catecholamines such as adrenaline and norepinephrine from extreme stress or a tumor secreting these chemicals is thought to play a central role. Excess catecholamines, when released directly by nerves that stimulate cardiac muscle cells, have a toxic effect and can lead to decreased cardiac muscular function or "stunning". Further, this adrenaline surge triggers the arteries to tighten, thereby raising blood pressure and placing more stress on the heart, and may lead to spasm of the coronary arteries that supply blood to the heart muscle. This impairs the arteries from delivering adequate blood flow and oxygen to the heart muscle. Together, these events can lead to congestive heart failure and decrease the hearts output of blood with each squeeze.Takotsubo cardiomyopathy occurs worldwide.