Acne also known as acne vulgaris caused by multiple factors.
Overproduction of a sebum that is skin natural oil increase under the influence of hormones.
This pair with shedding of exfoliating dead skin cells and plugs hair follicles.
The plug follicle become inflamed increased the growth of normal skin bacteria.
Medications such as, lithium, iodides, cortisone hormones, seizure medications or isoniazid can cause acne lesions.
There is no cure for acne, but certain measures prevent more breakouts. Acne can result in scarring that so minimizing breakouts is important.

Childhood acne - childhood acne may be of three type:
Neonatal acne
Infantile acne
Early onset acne vulgaris.

Neonatal acne - This is very common usually involves open and closed comedones, or some papules and pustules.
The development appears to be related to hormonal activity in utero and will resolve spontaneously 12-13 months after delivery without scarring.
No specific treatment is required except reassurance for parents.

Infantile acne - This usually develop at the age of 3-6 months.
They may be more extensive and inflammatory and does require treatment.
It may resolve spontaneously or persist.

Early onset Acne Vulgaris - In acne susceptible families, lesions start to become more from the age of 6 to 7 years and persist throughout adulthood.
Inflammation usually occurs at puberty may precede several years.
Inflammatory acne in children should warn underlying disorder.
Follicular Occlusion Triad - This includes three variants, one or more may be present in individual patients. All these represent inflammatory form of acne which consist of:
acne conglobata,
hidradenitis suppurativa,
Dissecting cellulitis.
Acne conglobate - This is a very serious form of inflammatory acne that is characterized by large cysts, large interconnecting comedones, draining abscesses and sinus tract formation.
Extreme scarring is common and difficult to prevent.
Aggressive treatment is essential.
Hidradenitis suppurativa - This is chronic inflammatory variant.
Major area affected are the axillae, groin, and perianal skin.
The lesions are deep cysts, nodules and form sinus tract.
Scarring is common and secondary infection occur.
Dissecting cellulitis of the scalp - nodules, cysts, and interconnected sinuses are present.
The scalp may be accompanied by scarring and irreversible hair loss.
Secondary infection is common.
Aggressive treatment is required.

Acne results in a variety of lesions.
The most common acne locations include the face, neck, chest, and back, where sebaceous glands are located.
Blackheads and whiteheads are follicular plugs that are either sitting below the skin surface known as whitehead or being exposed to the air known as blackhead.
Papules are pink to reddish-brown bumps that is small in size.
Pustules are pus-filled lesions,
Nodules are deeper pus-filled lesions.
Mild acne is consists of few papules/pustules and/or comedones.
Moderate acne increased the number of lesions.
Severe acne may include whiteheads, blackheads, papules, pustules, and may have painful nodules.
Acne can result in permanented scars, which can appear to be depressions in the skin, dark red or brown flat marks where the acne lesions were.

Grade 1: Comedones, occasional papules.
Grade 2: Papules, comedones, few pustules.
Grade 3: Predominant pustules, nodules, abscesses.
Grade 4: Mainly cysts, abscesses, widespread scarring.

Clogged pores cause acne. These may be attributed to:
Excess production of oil (sebum)
Dead skin cells
Ingrown hairs
Acne is usually associated with hormonal fluctuations mostly experienced during teenage but adults can experience acne. Acne may be non-inflammatory or inflammatory. Subtypes of acne within these two categories include:

Traditional treatments can help to prevent acne.
Wash acne prone areas with gentle soaps or cleansers.
Avoid skin irritants such as rubbing, abrasive scrubs and greasy products.
Water-based or noncomedogenic based products will help to reduce clogged pores.
There are also a variety of over-the-counter medications that may help to reduce the pimples, should be applied in a thin layer to the entire skin area on a regular basis improve acne but complete results seen after a few months.