DEAR DR. DONOHUE: I thought my husband had an ear infection, and I bought some drops to put in his ear. They didn’t work. Finally I got him to see a doctor. He doesn’t have an ear infection. He has seborrheic dermatitis. Is this catching? Should we be sleeping in separate beds? – M.J.

ANSWER: Seborrheic dermatitis (seborrhea) is a common skin affliction. It’s an inflammation of the skin and the skin’s oil glands. When it’s on the scalp, it’s dandruff, which comes in two forms: a dry variety with many flakes or a greasy kind with oily scales. You can think of seborrhea as an extreme form of the greasy kind of dandruff.

The scalp is not the only place where seborrheic dermatitis strikes. The eyebrows and eyelids, the vertical crease between the nose and the lower lip (nasolabial fold), the skin under the arms and the skin of the groin are all potential sites for it.

So are the ears. Ear involvement is commonly mistaken as an ear infection. Your story is told many times over every day in doctors’ offices.

The cause of seborrhea is unresolved. Some authorities implicate a yeast with the name “pityrosporum.” One element in treatment includes medicine that reduces the number of the pityrosporum yeast.

Treatment depends on the location of the problem. Ear involvement often responds to Cortisporin eardrops. They’re a mixture of cortisone and the antibiotic neomycin.

You don’t have to alter sleeping arrangements. Seborrhea is not catching.

DEAR DR. DONOHUE: I have lichen planus. My doctor has given me a cream, and I have used it faithfully for two weeks. I haven’t seen much of a change. Shouldn’t I have? Is this curable? Should I be using a different kind of medicine? – K.S.

ANSWER: The word “lichen” makes people think of mushrooms or fungi. Lichen planus is not related to either. It’s a fairly ordinary skin condition.

An outbreak begins with flat, many-sided, small, purplish points about the size of a small, printed “o.” They enlarge up to four-tenths of an inch (1 cm) in diameter. Close inspection shows crisscrossing white lines on the surface of each dot. The rash can be intolerably itchy.

The wrists, forearms, backs of the hands, thighs, lower back and genital skin are the sites predominantly involved. Some suffer an outbreak of the rash on the membranes of the mouth.

The cream you were prescribed must be one from the cortisone family. Such creams are standard therapy for this annoying skin eruption. Give it a chance. It might be only a little longer until it kicks in.

Hydroxyzine, an antihistamine, often affords relief from the itch. It is a sedating antihistamine, so many people can use it only before going to bed. It can make some people too groggy during the day.

There are some nice things to be said about lichen planus. Two-thirds of patients are burdened with it for less than a year. Of the remainder, many clear in the second year.

On the debit side, however, this is a skin disorder that can recur.

DEAR DR. DONOHUE: Please listen to my story. I woke up one morning with a backache, and I found I couldn’t move my legs. My husband called an ambulance to take me to the hospital. The entire first day consisted of tests without an answer to my plight. Finally, a neurologist diagnosed me as having transverse myelitis. I am home now, but my legs are still weak, and I have trouble walking. Does this ever get better? – H.C.

ANSWER: Here, “myel” refers to the spinal cord. Sometimes it refers to bone marrow. The “itis” indicates inflammation, and “transverse” means the inflammation cuts across the entire width of one segment of the spinal cord. Muscles whose nerve impulses come from the part of the cord below the inflamed segment can be weak to the point of paralysis, and pain is often an additional feature. Rarely, transverse myelitis marks the onset of multiple sclerosis. Sometimes it follows a viral infection, but quite often a cause is never found.

About one-third of patients will suffer permanent disability. The rest either recover or have a slight impairment.

DEAR DR. DONOHUE: Would you be so kind as to read the enclosed echocardiogram report? I have highlighted the sentence that bothers me. My doctor is not the least bit concerned, but he didn’t give me any explanation. Will you? – J.C.

ANSWER: The highlighted sentence says: “There is a trace of mitral regurgitation.”

The mitral valve regulates blood flow between the two left-sided heart chambers. It closes when the lower chamber contracts to pump blood out into the body. Closure keeps blood from being pumped back into the upper chamber.

Your valve has a “trace” leak (regurgitation). That means an inconsequential leak. You don’t have to trouble yourself about this. The valve is not giving you any trouble now, and it is unlikely to do so in the future. Many people have the same statement on their echocardiograms.

The pamphlet on valvular heart disease explains the nature and treatment of heart valve problems. Readers can obtain a copy by writing: Dr. Donohue – No. 105, P.O. Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.50 U.S./$6.50 Can. along with the recipient’s printed name and address. Please allow four weeks for delivery.

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.