What can occur with radiation doses higher than 5 Gy?

Radiation doses exceeding 5 Gray (Gy) can cause significant and lasting damage to skin tissues, leading to various adverse effects. At these higher exposure levels, skin hardening, known medically as sclerosis, and dermal atrophy are common. This is primarily due to the radiation's impact on the cellular structure of the skin, which can result in a reduction of the skin's ability to regenerate and repair itself.

Skin hardening occurs as a response to the damage, when the dermal collagen fibers become denser and less flexible. This change can lead to a feeling of tightness in the affected area. Dermal atrophy is characterized by a thinning of the skin layers, which happens because the underlying structures are diminished. Consequently, this can increase the risk of additional complications, including ulcers or infections, as the skin barrier becomes compromised.

In contrast, the potential outcomes listed in the other options do not align with the effects of such high radiation doses. While lower doses may allow for some recovery and limited effects like skin reddening, these signs do not reflect the serious, long-term changes occurring at doses above 5 Gy. Enhanced healing typically refers to the body's ability to recover from lesser doses of radiation, whereas high doses have the opposite effect,