Acne Vulgaris
On this page
Direct answer
An adolescent with open and closed comedones, inflammatory papules and pustules over the face, chest and back has acne vulgaris, a disease of the pilosebaceous unit driven by sebum production, Cutibacterium acnes colonisation, follicular plugging and inflammation. Grading as comedonal, mild, moderate papulopustular, or severe nodular drives therapy: topical retinoids with benzoyl peroxide for mild disease, added oral doxycycline for moderate disease, and oral isotretinoin 0.5 to 1 mg per kg daily aiming for a cumulative 120 to 150 mg per kg for severe, nodular or scarring acne. Isotretinoin is powerfully teratogenic, so pregnancy prevention is absolute, and it must never be combined with tetracyclines because of the shared risk of pseudotumour cerebri.
What you must remember
- Combination therapy beats monotherapy: benzoyl peroxide plus adapalene, or benzoyl peroxide plus clindamycin, addresses plugging, bacteria and inflammation together and benzoyl peroxide prevents resistance when topical antibiotics are used.
- Topical antibiotics as monotherapy are forbidden practice, because resistance emerges rapidly; retinoids are the comedolytic backbone of maintenance.
- Oral doxycycline 100 mg daily is added for moderate papulopustular acne, usually for a three-month course with topical continuation, never alone.
- Isotretinoin: 0.5 to 1 mg per kg per day, total cumulative dose 120 to 150 mg per kg for durable remission; cheilitis affects nearly everyone, xerosis and epistaxis are expected, triglycerides and transaminases are checked at baseline and if risk factors exist.
- Teratogenicity is absolute: two reliable contraception methods or documented abstinence, monthly pregnancy tests, and a washout of at least one month after stopping before conception is attempted.
- Hormonal therapy, combined oral contraceptives containing ethinyloestradiol with cyproterone acetate or drospirenone, or spironolactone, suits women with menstrual flares, hirsutism or polycystic ovary features, after screening for contraindications.
- Indian skin specifics: post-inflammatory hyperpigmentation often troubles more than active lesions, mandating early treatment and photoprotection; keloidal scarring may need intralesional steroid once activity is controlled.
A graded pathway from comedones to clearance
A 19-year-old student presents with two years of facial acne, now with deep painful nodules over the jawline and early scarring of both cheeks. He has used assorted over-the-counter creams; examination shows comedones, papules, pustules and nodules with post-inflammatory hyperpigmentation.
Step one: grade and seek drivers. This is severe nodular acne with scarring, an automatic isotretinoin candidate; screen for anabolic steroid use, and consider polycystic ovary syndrome in women with irregular periods and hirsutism.
Step two: run the conventional ladder where appropriate. Comedonal disease receives adapalene 0.1 per cent gel at night with benzoyl peroxide wash in the morning; mild inflammatory disease adds topical clindamycin with benzoyl peroxide; moderate disease adds oral doxycycline 100 mg daily for up to three months. His severity short-circuits this ladder.
Step three: start isotretinoin properly. Baseline lipids and liver tests, a course beginning at 0.5 mg per kg daily with food, titrating toward 1 mg per kg, planning a cumulative 120 to 150 mg per kg; counsel on cheilitis, dryness, photosensitivity, mood change, night vision and avoiding waxing during therapy.
Step four: manage the pitfalls. Stop all tetracyclines beforehand, since the combination risks intracranial hypertension; no blood donation during and for a month after therapy; document monthly pregnancy tests in women of childbearing age.
Step five: deal with the aftermath. Persistent hyperpigmentation fades over months with strict sun protection and azelaic acid; atrophic scars are addressed by microneedling, subcision or fractional laser after a durable remission; keloids receive intralesional triamcinolone.
Where the exam tries to catch you
The two contraindication questions recur every year: isotretinoin with pregnancy, which is absolute, and isotretinoin plus tetracyclines, which raises intracranial pressure; the correct companion prescriptions are food, emollients and lip balm. The second trap is the antibiotic answer, where a stem of pustular acne is treated with oral antibiotics alone, a practice that breeds resistance and relapse; the correct answer pairs benzoyl peroxide or a retinoid with the antibiotic. The viva favourite is the total dose logic: relapse is likelier when cumulative 120 to 150 mg per kg is not reached, and milder disease may use lower-dose longer courses deliberately.
Frequently asked questions
Which topical combination is preferred for mild acne?
A retinoid such as adapalene with benzoyl peroxide, applied together or as a fixed combination, treating both comedones and inflammation.
What cumulative isotretinoin dose aims for durable remission?
120 to 150 mg per kg over the course, using 0.5 to 1 mg per kg daily, with relapse more likely below this total.
Why is isotretinoin never combined with doxycycline?
Both raise intracranial pressure, so co-prescription risks pseudotumour cerebri.
What monitoring does isotretinoin require?
Baseline and follow-up lipids and liver enzymes, monthly pregnancy testing in women of childbearing potential, and counselling about dryness, mood and photosensitivity.
Which hormonal options suit women with acne?
Combined oral contraceptives with antiandrogenic progestins, or spironolactone, particularly with menstrual flares or polycystic ovary features.
What is the emergency counselling point for female patients?
Absolute contraception during therapy and for at least a month afterwards, because isotretinoin is among the most teratogenic drugs in common use.