Hair, ear and foot hygiene

Cerumen is not a dead deposit waiting to be dug out. The skin of the ear canal migrates slowly outwards from the ear drum towards the opening, like a very slow conveyor belt, and the jaw movements of talking and chewing help the wax along. Along the way the wax, which is a mixture of secretions from glands in the canal skin and shed cells, traps dust particles, repels water and keeps the canal skin slightly acidic, which discourages bacterial and fungal growth. This is why the ear needs no internal cleaning: the canal is designed to clear itself. The system fails in a predictable way. When a pin, a cotton bud or a fingernail pushes wax back towards the drum, the wax is compacted into a plug instead of being carried out. As the plug presses on the drum, the person reports a blocked, full sensation and a dulled hearing, sometimes with ringing, and a plug can also be pushed against the drum after swimming or bathing, when the wax has absorbed water and swelled. Impacted cerumen is one of the commonest reversible causes of hearing loss, and it matters in nursing because hearing loss looks like confusion, poor attention or non-adherence in older patients. Removal is a clinical procedure: the doctor may soften the wax with drops so that the canal clears itself, or remove it under direct vision by syringing or with a fine instrument, having first checked that the drum is intact. Nurses teach the rule and make the referral; they never improvise the removal.

The scalp is an oily, warm, hair-covered surface, and that combination explains both dandruff and the fungal infections that follow it. Each hair follicle is served by one or more sebaceous glands that empty their oil into the follicle, and the scalp has a dense population of these glands compared with most of the body. Oil production is under hormonal control, which is why the scalp becomes greasier after puberty and why dandruff is so common in adolescents and young adults. When production rises, the oil film on the scalp thickens and the normal shedding of dead skin cells, which is invisible when the scalp is balanced, starts to clump into visible flakes. The flakes are not dirt and they are not a sign that the person has not washed; they are the scalp surface responding to too much oil. Several species of yeast that live harmlessly on the scalp, commonly Malassezia, multiply in that richer oil film and irritate the skin, increasing both flaking and itching. This is the mechanism behind ordinary dandruff, and it separates two things students often confuse. Dandruff is a scalp reaction, annoys but does not infect. Tinea capitis, the ringworm of the scalp named in the notes, is a genuine fungal infection of the hair follicle and hair shaft by dermatophyte moulds; it can cause patches of broken hair and scaling, and it spreads between children on shared combs, hats, pillows and clippers and sometimes from animals. It needs antifungal treatment prescribed by a clinician, and the nurse’s role is to recognise the difference, teach that combs and towels must not be shared, and follow up the whole household. Two practical rules follow. Wash at least twice weekly as the notes recommend, because regular washing removes the accumulated oil rather than letting the yeast habitat thicken. And never share a comb or clipper, because both dandruff and Tinea capitis pass from head to head on them.

Head lice control fails when it is treated as a family embarrassment rather than a population problem, and the biology explains why. Pediculus humanus capitis is an insect that lives only on the human scalp and feeds on blood several times a day. The adult female glues each egg, the nit, to a hair shaft within a few millimetres of the scalp, where the temperature is right for incubation; the nit is cemented on and does not wash off or fall away with normal combing, which is why nits close to the scalp are the most reliable evidence of an active infestation and nits far down the hair may be old shells. Eggs hatch in about a week, and the nymph passes through three moults before becoming an adult in roughly another week to ten days. Because the insect cannot fly or jump, it moves by walking from one hair to another when two heads touch, and that is exactly what happens when children lean over the same book, share a mat at nap time, or play head to head. This is why the notes say that children are especially prone and that close contact in school environments spreads lice. Sharing combs, brushes, caps and headrests can also transfer a louse, but head-to-head contact dominates. Itching is not caused by the bite itself but by an allergic reaction to louse saliva, so a child can be infested for weeks before scratching begins, and by then the class has been exposed. Treatment follows the biology: a pediculicide or fine-toothed wet combing repeated according to the product instructions, because the first application may not kill eggs and a second round is needed after they hatch; treating the whole household at the same time; and washing or isolating combs, hats and bedding. Shaving the head hair is possible in heavy infestation, but blades must never be shared, as the notes warn, because blood-borne viruses such as hepatitis B and HIV can pass on a contaminated blade. The nurse’s key message is that lice prefer clean hair as much as dirty hair, so screening a whole class protects children from blame.

Podoconiosis is one of the few chronic diseases whose cause is a mineral rather than an organism, and knowing that changes both prevention and treatment. In highland areas where the soil is derived from volcanic rock, the ground contains very fine clay particles rich in silica and aluminium. Walking barefoot, day after day, on that soil produces constant micro-abrasion of the skin of the soles and between the toes; the particles enter through these microscopic breaches and are carried by the lymph to the lymph nodes of the groin. The nodes react with chronic inflammation and eventually scar, and because the lymph vessels can no longer drain the leg normally, fluid collects and the foot and lower leg swell. The swelling is firm and bilateral, and over years the skin thickens and takes on a rough, mossy appearance, which is why the disease is also called mossy foot. The notes rightly say that it is a reaction in the body to very small soil particles that have passed through the skin of the feet, and that it is common in certain parts of Ethiopia. Several features follow from the mechanism and matter for nursing. First, it is not infectious: it cannot be caught from another person, and patients must not be isolated or their families stigmatised, which has been one of the great social harms of the disease. Second, it is preventable by wearing shoes at all times, including while farming, and the effectiveness of shoes is the strongest single argument for shoe distribution in endemic districts; the shoes work because they stop the particles before the skin is breached. Third, in an affected person, treatment combines two things. The advised washing and drying of the feet, carried out carefully and daily, keeps the skin intact and removes soil, and this is combined with elevation of the leg, exercise of the foot, and elastic bandaging or compression garments to move the lymph and reduce the swelling; in endemic areas treatment is provided as a standard package through health centres. The nurse’s tasks are therefore to assess the swelling, to distinguish it from other causes such as cardiac or kidney oedema, to teach consistent shoe wearing, and to demonstrate the washing, drying and bandaging routine at every visit, because the disease progresses when the routine lapses.