Acne is an inflammatory, usually chronic, disease of the sebaceous glands, characterized by papules, tubercles, or pustules, or a mixture of these lesions, and seated usually about the face.

At what age does acne usually occur?

Acne mostly occurs between the ages of fifteen and thirty, at which time the glandular structures are naturally more or less active.

Symptoms of acne.

Irregularly scattered over the face, and in some cases also over the neck, shoulders and upper part of the trunk, are to be seen several, fifty or more, pin-head- to pea-sized papules, tubercles or pustules; commonly the eruption is of a mixed type (acne vulgaris), the several kinds of lesions in all stages of evolution and subsidence presenting in the single case. Interspersed may generally be seen blackheads, or comedones. The lesions may be sluggish in character, or they may be markedly inflammatory, with hard and indurated bases. In the course of several days or weeks, the papules and tubercles tend gradually to disappear by absorption; or, and as commonly the case, they become pustular, discharge their contents, or dry and slowly or rapidly disappear, with or without leaving a permanent trace, new lesions arising, here and there, to take their place. In exceptional instances the eruption is limited to the back, and in these  cases the eruption is usually extensive and persistent, and not infrequently leaves scars.

What do you understand by acne punctata, acne papulosa, acne pustulosa, acne indurata, acne atrophica, acne hypertrophica, and acne cachecticorum?

These several terms indicate that the lesions present are, for the most part, of one particular character or variety.

What course does acne pursue?

Essentially chronic. The individual lesions usually run their course in several days or one or two weeks, but new lesions continue to appear from time to time, and the disease thus persists, with more or less variation, for months or years. In many cases there is, toward the age of twenty-five or thirty, a tendency to spontaneous disappearance of the disease.

Indirect or predisposing causes of Acne

Digestive disturbance, constipation, menstrual irregularities, chlorosis, general debility, lack of tone in the muscular fibres of the skin, scrofulosis; and medicinal substances such as the iodides and bromides internally, and tar externally.

Working in a dusty or dirty atmosphere is often influential, resulting in a blocking-up of the gland ducts. Workmen in paraffin oils or other petroleum products often present a furuncle-like acne.

The disease is more common in individuals of light complexion.

Difficulty in the diagnosis of acne?

Not if it be remembered that acne eruption is limited to certain parts and is always follicular, and that the several stages, from the comedo to the matured lesion, are usually to be seen in the individual case.

What is the pathology of acne?

Primarily, acne is a folliculitis, due to retention or decomposition of the sebaceous secretion or to the introduction of a micro-organism; subsequently, the tissue immediately surrounding becoming involved, with the possible destruction of the sebaceous follicle as a result. The degree of inflammatory action determines the character of the lesions.