red rash on arm(s)

発疹や手にバンプ, 皮膚のしこり, 腫れぼったい顔, redness in skin in one area

かゆみ, 発疹, 発疹や皮膚にバンプ, redness in skin in one area

Atopic dermatitis, sometimes called eczema, is a kind of dermatitis, an atopic skin disease. Atopic dermatitis afflicts humans, particularly young children; it is also a well-characterized disease in domestic dogs. 

発疹や皮膚にバンプ, 膿皮膚から排出, 顔の発疹, redness in skin in one area

Cellulitis is an inflammation of the connective tissue underlying the skin, that can be caused by a bacterial infection. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, burns, insect bites, surgical wounds, or sites of intravenous catheter insertion. 

かゆみ, 発疹や皮膚にバンプ, 顔の発疹, redness in skin in one area

A sunburn is a burn to living tissue such as skin or leaves produced by overexposure to ultraviolet (UV) radiation, commonly from the sun's rays. A similar burn can be produced by overexposure to other sources of UV such as from tanning lamps, or occupationally, such as from welding arcs. 

しこりor女性の脚の付け根の腫れ, 皮膚のしこり, 顔の発疹, redness in skin in one area

An abscess is a collection of pus that has accumulated in a cavity formed by the tissue on the basis of an infectious process (usually caused by bacteria or parasites) or other foreign materials (e.g. splinters or bullet wounds). 

乾燥肌, 発疹, 発疹や腕に出会う, 発疹や足にバンプ

Keratosis pilaris (KP) is a very common genetic follicular condition that is manifested by the appearance of rough bumps on the skin and hence colloquially referred to as "chicken skin". It most often appears on the back and outer sides of the upper arms (though the lower arms can also be affected), and can also occur on the thighs and tops of legs, flanks, buttocks or any body part except glabrous skin (like the palms or soles of feet). 

発疹, 発疹や皮膚にバンプ, 皮膚のしこり, redness in skin in one area

Urticaria or hives is a relatively common form of allergic reaction that causes raised red skin welts. Urticaria is also known as nettle rash or uredo. These welts can be 5 mm (0.2 inches) in diameter or more, itch severely, and often have a pale border. 

冷たい手と足, 手が冷たい, 腕に発疹, rash on foot (feet)

Livedoid vasculitis (also known as "livedo vasculitis", "livedo reticularis", and "livedoid vasculopathy") is a vascular disorder mostly affecting women. It may be aggravated by exposure to cold and occurs most often in the lower extremities. 

腕に発疹, 腫れ足首, 膿皮膚から排出, redness in skin in one area

Cellulitis is an inflammation of the connective tissue underlying the skin, that can be caused by a bacterial infection. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, burns, insect bites, surgical wounds, or sites of intravenous catheter insertion. 

しこりや脚の腫れ, 発疹や皮膚にバンプ, 皮膚のしこり, 顔の発疹