It could be eczema, sweat dermatitis, allergic reactions, herpes, etc.
You need to wash the areas several times with fresh water. Do not use any cosmetic products at the sites.
Apply calamine lotion at the site of the lesions and see if it helps. You could take some oral antihistamine medications like cetrizine or loratadine. You need to maintain a good personal hygiene .
Anti-itch drugs, often antihistamine, may reduce the itch during a flare up of eczema, and the reduced scratching in turn reduces damage and irritation to the skin.
For mild-moderate eczema a weak steroid may be used (e.g. hydrocortisone or desonide), whilst more severe cases require a higher-potency steroid (e.g. clobetasol propionate, fluocinonide).
Eczema can be exacerbated by dryness of the skin. Moisturizing is one of the most important self-care treatments for sufferers of eczema. Keeping the affected area moistened can promote skin healing and relief of symptoms.
http://en.wikipedia.org/wiki/Eczema
Let us know if you need any further information.
It would be advisable to consult a skin specialist for your symptoms and a proper clinical examination.
Let us know if you need any other information and post us on how you are doing.
Regards.
Hi,
These bumps seem to be infected hair follicles.Folliculitis usually appears as small, white-headed pimples around one or more hair follicles but deep or recurring folliculitis may need medical treatment.
When the hair follicles get damaged, they may be invaded by viruses, bacteria or fungi, leading to infections such as folliculitis. The most common causes of hair follicle damage include friction from shaving or tight clothing, excessive perspiration, inflammatory skin conditions, including dermatitis and acne.
You can apply an antibiotic cream on the areas but in your case a course of oral antibiotics will be required since they seem to be quite extensive.
ref: http://www.mayoclinic.com/health/folliculitis/DS00512/DSECTION=treatments%2Dand%2Ddrugs