30
Comedonal acne
Open comedones (blackheads) and closed comedones are the first acne lesions to appear. Some become inflamed and become papules or pustules.
Closed comedones, or whiteheads, have a very small orifice. This impedes drainage. They respond slowly to treatment.
Open comedones remain for months. Stretch the skin for support, and remove them with a comedone extractor.
Open comedones in the ear are unsightly. They respond slowly to topical treatment and can be removed with a comedo extractor and gentle pressure.
DESCRIPTION
Comedones (whiteheads are closed comedones and blackheads are open comedones) are the primary lesions of acne. Sebum production increases, follicular wall cells fail to desquamate to the surface in the normal manner, and Propionibacterium acnes grows in the sebum-cell mixture and forms a plugged pore or a microcomedo and then a visible comedo.
HISTORY
Acne begins with the development of comedones. These appear before other signs of puberty.
PHYSICAL FINDINGS
• First, sebaceous glands become more active, and the face and scalp become oily. • Blackheads and whiteheads first appear on the nose. Later, they form on the forehead, cheeks, and finally chin. Chest and back tend to be the last areas affected. Comedones also form in and behind the ears.
TREATMENT
Retinoids are comedolytic and are drugs of first choice. Apply q.o.d., q.d., or b.i.d. as tolerated. Creams are for dry skin and are less irritating. Gels are for oily skin.
• Tretinoin: Retin-A gel (0.025%, 0.01%) 15 g, 45 g; Retin-A cream (0.1%, 0.05%, 0.025%) 20 g, 45 g.; Retin-A solution (0.05%) Less irritating: Retin-A micro (0.04%, 0.1%) 20 g, 45 g. Less irritating: Adapalene (Differin) gel (0.1%, 0.3%) 45 g; Differin cream, or lotion (0.1%) 45 g, 59 mL. • Azelaic acid (Finacea gel) (15%) 15 g: comedolytic and antibacterial. Adapalene is unaffected by sunlight. Tretinoin and tazarotene cause sensitivity to sun. Tazarotene is pregnancy category X.
Drying, peeling antibacterial agents are used alone or in combination with retinoids. • Benzoyl peroxide-clindamycin combinations: Benzaclin gel 25 g, 50 g; Duac gel 45 g; Acanya gel 50 g. • Benzoyl peroxide-tretinoin combinations: Vetlin gel 30 g, Ziana gel 30 g, 60 g. Dapsone (Aczone gel) (5%) 30 g, 60 g.
