Acne Mechanica and Flat Warts

Case 1:

This 14-year-old girl who is being treated for acne presents for a follow-up visit. Acne has cleared on her chest and face, except for the forehead. She tried tretinoin, clindamycin/benzoyl peroxide, and a sulfur/sulfacetamide compound with limited results. Her menses are regular, and she does not have excessive facial or body hair.

What do you suspect?
A. Polycystic ovary syndrome.
B. Congenital adrenal hyperplasia.
C. Antibiotic-resistant Propionibacterium acnes.
D. Acne cosmetica.
E. Acne mechanica.

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Case 1: Acne mechanica

Acne mechanica, E, is caused or aggravated by heat, occlusion, constant pressure, and repetitive friction against the skin. For this patient, who is a competitive rider, her cowgirl hat was the culprit.

Common sports-related causes of acne mechanica are:
•Helmets and helmet straps, especially those worn by football and hockey players and motorcycle riders.
•Shoulder pads and straps worn by football players.
•Tight uniforms made of synthetic fabric.
•Tight headbands worn by soccer players and runners.
•Straps and packs on backpacks.
Other common causes of acne mechanica are:
•Straps used by soldiers for weapons and equipment.
•Headbands worn for long periods.
•Musical instruments, such as the violin, tucked against the neck for hours.
•Tight fur caps worn for long periods.
•Tight clothing, such as jeans and underwear made of synthetic fabric.
•Snug bra straps.

Polycystic ovary syndrome and congenital adrenal hyperplasia are characterized by signs of hyperandrogenism, such as hirsutism. Resistant bacteria should respond to sulfur and benzoyl peroxide-based antibiotics. Acne cosmetica usually occurs in the distribution of the applied cosmetic.

Case 2:

A combination clindamycin/benzoyl peroxide product has failed to resolve these lesions on a 15-year-old girl’s forehead. She does not have acne elsewhere.

Which of the following would you offer?

A. Tretinoin cream.
B. Adapalene cream.
C. Tazarotene cream.
D. Oral minocycline.
E. Reassurance with no treatment at this time.

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Case 2: Flat warts

This patient had flat warts that resembled comedonal acne. Tretinoin cream, A, adapalene cream, B, and tazarotene cream, C, have all been successful in treating this pesky viral infection.

Case 3:

An otherwise healthy 29-year-old woman seeks treatment of acne of recent onset on her cheeks. She has not noted any change in her menses, and she has been taking the same oral contraceptive for 2 years. Previously, she was evaluated by another physician who told her the condition was hormonal and did not offer any treatment.

What action would you take?

A. Prescribe a different oral contraceptive.
B. Add an oral antibiotic, such as doxycycline.
C. Start treatment with a topical antibiotic, such as clindamycin.
D. Start treatment with a topical retinoid, such as tretinoin.
E. Offer her no treatment other than reassurance.

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Case 3: Rosacea

This patient had changes consistent with rosacea. Late-onset acne can occur and can be hormonal. However, when the pattern is mid face with inflammatory papules without comedones, the differential should be expanded to include rosacea. Additional history taking often elicits the traditional aggravating factors that increase blood flow to the face, such as hot or cold weather, stress, spicy foods, and exercise. Include an evaluation of the eyes and eyelids in the workup because they are involved in up to 40% of patients with rosacea.¹ Treatment options include both topical and oral antibiotics (B and C).

Case 4:

What appears to be acne on the cheeks of this 9-year-old girl has not responded to topical clindamycin. She was unable to tolerate tretinoin.

Which of these treatments is most likely to be effective?

A. Adapalene cream.
B. Erythromycin gel/solution.
C. Oral doxycycline.
D. Salicyclic acid cream.
E. An oral contraceptive.

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Case 4: Keratosis pilaris

This child has keratosis pilaris, which is a marker for atopic dermatitis. Affected patients typically have sensitive skin, which makes it difficult for them to tolerate tretinoin. Adapalene, A, can be effective if it is tolerated, as can salicylic acid cream, D.

The alcohol base in the topical erythromycin would not be well tolerated. Doxycycline and oral contraceptives play no role in the treatment of keratosis pilaris, which should resolve by age 20.

References:

REFERENCE:

1.

Quarterman MJ, Johnson DW, Abele DC, et al. Ocular rosacea. Signs, symptoms, and tear studies before and after treatment with doxycycline.

Arch Dermatol.

1997;133:49-54.