D

DANDRUFF

Dandruff (pityriasis capitis) is mainly a physiological process, the result of normal desquamation of scale from the scalp. It is most prevalent in adolescence and worst around the age of 20.

Treatment (if necessary)

Shampoos: zinc pyrithione (e.g. Dan-Gard, Head and Shoulders) or selenium sulfide (e.g. Selsun)

Method: massage into scalp, leave for 5 mins, rinse thoroughly twice wkly

Persistent dandruff

Persistent dandruff with severe flaking and itching indicates seborrhoeic dermatitis or psoriasis in which the scalp skin feels lumpy.

Treatment

Shampoos: coal tar + salicylic acid compound (Sebitar) shampoo or Ionil T plus shampoo

Method: as above, followed by Sebi Rinse or ketoconazole (Nizoral) shampoo

If persistent, esp. itching, and Nizoral shampoo ineffective, use a corticosteroid (e.g. betamethasone scalp lotion).

DEAFNESS AND HEARING LOSS

Deafness is defined as impairment of hearing, regardless of its severity. It is a major community health problem requiring a high index of suspicion for diagnosis, esp. in children. Deafness may be conductive, sensorineural (SND) or a combination of both (mixed).

• Deafness occurs at all ages but more common in the elderly—50%>80 yrs—that could be helped by a hearing aid.

• The threshold of normal hearing is from 0 to 20 dB, about the loudness of a soft whisper.

• Degrees of hearing impairment:

  • – mild = loss of 20–40 dB (soft spoken voice is 20 dB)

  • – moderate = loss of 40–60 dB (normal spoken voice is 40 dB)

  • – severe = loss of 70–90 dB (loud spoken voice)

  • – profound = loss of over 90 dB (shout is 90–120 dB)

• People who have worked in high noise levels (>85 dB) are more than twice as likely to be deaf.

• There is a related incidence of tinnitus with deafness.

Deafness in children

Deafness in childhood is relatively common and often goes unrecognised. A mother who believes that her child may be deaf is rarely wrong in this suspicion.

Screening

The aim of screening should be to recognise every deaf child by the age of 8–10 mths—before the vital time for learning speech is wasted. Optimal screening times:

• 8–9 mths (or earlier)

• school entry

No child is too young for audiological assessment. Informal office tests are inadequate to exclude hearing loss.

Otosclerosis

Features