S e p t e m b e r 2 0 0 8 • w w w. s k i n a n d a l l e r g y n ew s . c o m Pediatric Dermatology 41

Using benzoyl peroxide in the morningand a retinoid at night provides syner-gistic effects, but applying anything at thesame time as a retinoid is likely to causeskin irritation, he added.�� Pustules. If pustules are present, adda twice-daily topical antibiotic (ery-thromycin or clindamycin), which is safeto combine with benzoyl peroxide butshouldn’t be applied at the same time asa tretinoin.

Some vehicles may dry the skin, whileothers may feel greasy, either of whichcan work to the advantage of individual

patients. Rarely, clindamycin may causediarrhea.

Acne on the back or chest often doesnot respond well to retinoids or benzoylperoxide, and teenage boys often won’tadhere to any topical therapy (includingtopical antibiotics), so systemic antibi-otics may be needed before you can getthem to transition to topical therapies,Dr. Lane noted. Tetracyclines are his firstchoice for systemic therapy, followed byerythromycin.

Systemic side effects can cause GI irri-tation or yeast vaginitis and may decreasethe effectiveness of oral contraceptives.

Some adolescent girls with acne may

benefit from hormonal therapy, but Dr.Lane leaves this approach to the patient’sprimary care physician.�� Cysts and scars. More aggressive treat-ment is appropriate for acne with cystsand scars, and many of these patients willend up receiving isotretinoin from a der-matologist who can follow them careful-ly for numerous potential side effects.

For patients aged 18-25 years, isotre-tinoin therapy will get rid of acne for 10years or longer in 30%, and 40% will haverecurrent acne that responds to topicaltherapies or antibiotics. The odds areeven better for patients aged 12-15 years,Dr. Lane said. ■

Continued from previous page IncontinentiaPigmenti NotAll That Rare

B Y S H E R RY B O S C H E R T

San Francisco Bureau

S TA N F O R D, C A L I F. — A rare geneticdisorder that usually is lethal to male babiesand can leave abnormalities of the skin,eyes, and other body parts in females, maybe more common than originally thought.

Incontinentia pigmenti is caused by amutation in the IKBKG gene (also knownas NEMO), which resides on the X chro-mosome. A genetic diagnosis can be help-ful in females with suspected incontinentiapigmenti because they carry a 50:50 risk ofpassing the mutation on to their offspring,Dr. Louanne Hudgins said at a pediatric up-date sponsored by Stanford University.

Typically, blistering on the skin of aneonate or infant progresses to a wart-likerash, swirling macular hyperpigmentation,and linear hypopigmentation.

Other ecto-dermal-derivedtissues are af-fected, too. Pa-tients with in-c o n t i n e n t i apigmenti oftenhave patchyalopecia of thescalp, dystroph-ic nails, andtooth abnor-malities (fewerteeth than nor-mal or abnor-mal tooth for-

mation, such as a cone-shaped tooth).Associated eye problems are the most sig-nificant finding in survivors with inconti-nentia pigmenti. They often have retinalvascular proliferation, which can lead toretinal detachment.

“The mother may look completely nor-mal or may have linear patches without asmuch hair” as a typical scalp, but genetictesting can identify incontinentia pigmen-ti in 80% of cases, said Dr. Hudgins, pro-fessor of pediatrics and chief of medicalgenetics at Stanford.

She and her associates used to test forincontinentia pigmenti only in girls whohad all of the associated findings, andrarely made the diagnosis. More recently,however, “we’ve been doing the testing inkids with a few findings, and are findingthe mutation. I think it’s more commonthan we thought it was,” she said. “In ourgenetic disorders of the skin clinic, we seeas many as four or five cases per year” ofincontinentia pigmenti.

Even with a presumptive diagnosis, it’simportant to order an ophthalmologicexam. “If this child is at risk for retinal de-tachment, you need to have that child fol-lowed by ophthalmology on a regular ba-sis so you can maintain the best visionpossible,” she said. Dental and dermato-logic evaluations also are warranted. “Ifthey have ongoing skin problems, it’s cer-tainly a good idea to have a dermatologistfollow them,” said Dr. Hudgins, who re-ported having no conflicts of interest. ■

Patients withincontinentiapigmenti oftenhave patchyalopecia of thescalp, dystrophicnails, and toothabnormalities(few or abnormalshaped).