DEAR DR. DONOHUE: I have never seen cellulitis discussed in your column. Please explain what it is. I have had it twice in my leg. My doctor gives me an antibiotic but doesn’t say how to prevent it. How do you? – J.E.

ANSWER: Others are going to accuse me of overdoing cellulitis. However, it’s an often-asked question and it is a relatively common affliction, so it deserves rehashing.

Cellulitis is an infection of skin cells and of the fat that lies beneath the skin. The offending germ is usually the staph or strep germ. Either one can gain entrance to the skin through a scratch or puncture wound so tiny that people are unaware of it.

Once the germs gain entrance, they multiply, and the infection spreads. The skin turns red, becomes hot and is often swollen. Daily the margin of the infection expands until the entire leg (or arm or back or shoulder) is involved, and the intensity of the pain gains momentum as the infection enlarges. People can be feverish and feel like they are completely wiped out.

Treatment is with antibiotics. In severe cases, hospitalization is necessary so antibiotics can be given through a drip into a vein. That way a high blood level of antibiotic is rapidly obtained and the advance of the infection is stopped.

People like you who suffer two or more bouts of cellulitis have to search for a cause of the repeated infection. Swollen ankles from heart failure or varicose veins make it difficult for the body to fight an infecting germ in that area. The swelling must be remedied to prevent repeated infections. Or, athlete’s foot can be the door by which germs gain access to the skin of the leg. Eradicating it eradicates the return of cellulitis. Eczema of the skin is another invitation for cellulitis. If no portal of entry for germs is found, then some doctors choose to treat people who have repeated infections with a monthly shot of penicillin or a daily oral dose of penicillin or another antibiotic.

DEAR DR. DONOHUE: Frequently I wake with a headache. I know that such headaches are supposed to be a sign of high blood pressure, but my pressure is normal. Please tell me some other causes. – M.P.

ANSWER: Anxiety, depression and insomnia can lead to early-morning headaches. A bed partner who snores loudly is another cause. Heavy alcohol use can give people a headache on wakening.

An important cause is sleep apnea. That’s the condition where a person stops breathing during sleep for 10 or more seconds and does so many times during the night. Often, sleep apnea is heralded by loud snoring that abruptly stops when the no-breathing episodes take place.

Heart, lung and thyroid disease also can be behind such headaches.

Have your family doctor have a go at you to see what might turn up.

The headache pamphlet discusses all headache varieties, their causes and their treatments. Readers can obtain a copy by writing: Dr. Donohue – No. 901, P.O. Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.50 U.S./$6.50 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: I am 14 and feel like a freak because one of my breasts is larger than the other. It embarrasses me, and I would like to know if there is surgery to correct this. Is the recovery from such surgery long? – P.P.

ANSWER: At your age, most girls have an inequality in breast size. Some women keep this inequality into adult life, but most see the difference between the two breasts disappear as puberty progresses.

There is nothing you should do at the present time aside from using a padded bra. I know that is something you don’t want to hear, but having surgery at your age would be foolish. You shouldn’t think about such a remedy now. Wait until you are well into your 20s before contemplating such a step. Care to make a bet? I bet you won’t ever need surgery.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.