Actinic purpura is a benign clinical entity resulting from sun-induced damage to the connective tissue of the dermis. Actinic purpura is characterized by ecchymoses on the extensor surfaces of the forearms and the dorsa of the hands that usually last 1-3 weeks. See the image below.
Bateman  first described the condition in 1818 when he noted dark purple blotches and determined that they were due to the extravasation of blood into the dermal tissue. Hence, it is sometimes called Bateman purpura.
It is common in elderly individuals and usually occurs after unrecognized minor trauma to the respective areas.
Clinical aspects of dermatoporosis include morphological markers of fragility, such as senile purpura, stellate pseudoscars, and skin atrophy.  The concept of the syndrome term dermatoporosis has been used to compare it to osteoporosis, implying both should be prevented and treated to avoid complications.
The purple macules and patches of this condition occur because red blood cells leak into the dermal tissue. This extravasation is secondary to the fragility of the blood vessel walls caused by ultraviolet radiation–induced dermal tissue atrophy.  This atrophy renders the skin and microvasculature more susceptible to the effects of minor trauma and shearing forces. The insult to the skin is typically so minor that isolating it as a cause of the ecchymoses can be difficult.
Notably, no inflammatory component is found in the dermal tissue. The absence of a phagocytic response to the extravascular blood has been postulated to be responsible for delaying resorption for as long as 3 weeks.
Actinic purpura may be, along with osteoporosis, a sign of collagen loss in skin and bone.  This causal loss of skin collagen has been confirmed when collagen was expressed absolutely, instead of as a percentage or ratio. That is, women have less collagen than men and it decreases by 1% a year in exposed and unexposed skin. These changes in skin collagen may correspond to changes in bone density. The hypothesis is that the changes in skin collagen also occur in bone collagen, leading to the associated changes in bone density.
Actinic purpura is an extremely common finding in elderly individuals, occurring in approximately 11.9% of those older than 50 years. Its prevalence markedly increases with years of exposure to the sun.
A study of the prevalence of dermatoses in 75 elderly residents in a long-term care facility in Santos, Brazil, found 280 dermatoses, with an average number of 3.73 per elderly person and 32 different types of dermatoses.  Actinic purpura was evident in 29.3% of them.
The effects of chronic sun exposure with the resultant ultraviolet radiation–induced skin changes occur more often and are more pronounced in fair-skinned individuals than in others.
Both sexes are equally affected.
Actinic purpura occurs almost exclusively in the elderly population, though it may sporadically occur in younger people. The incidence varies with respect to age. Approximately 2% of those aged 60-70 years and as many as 25% of those aged 90-100 years can have the purpuric lesions.
Individual lesions of actinic purpura generally resolve within 1-3 weeks. Residual hemosiderosis may occur. Purpuric lesions usually continue to occur during the individual's life. The ecchymoses may be cosmetically distressing and may leave dyspigmentation or scarring, but the lesions are not associated with any serious complications.
Reassure the patient that this condition is benign. Emphasize the absolute necessity of using sunscreen and barrier protection to prevent further photodamage. Inform patients that sunscreens do not reverse photodamage. Instruct patients to minimize any trauma to the skin where the purpuric lesions are present.