In the past, very few people with Sickle Cell Disease
(SCD) survived to adulthood. More effective measures and innovations
against infections and other complications mean that people with SCD now
live longer. Most reach adulthood (Leikin, et al, 1989)
and some live to their 50's, 60's and 70's (Brozovic &
Davies 1987, Grey, et al 1991). The severity of the condition and
the extent to which people are affected remain highly variable.
Various aspects of adult life have potentially important consequences for
adaptation to SCD, some of which might be expected to act for the better
and others for the worse. As young people reach adulthood they must learn
to take greater responsibility for the management of their condition. They
may be exposed to popular misconceptions and prejudices about SCD and may
face new and difficult challenges in the work-place and their social life,
(see links to psychology
& housing).
There have been fewer studies done on adults with SCD, the main areas of
investigations are psychological adjustments, coping strategies and
effects on life styles which have been found to be similar (see
link to psychology).
Management of pregnancy in SCD patients (see link to
pregnancy and ante-natal)
SICKLE CELL DISEASE
SCD occurs when the Hb S gene is inherited from one parent and either the
Hb S gene or an interacting abnormal Hb gene from the other. The more
common forms of Sickle Cell Disease include sickle cell anaemia (Hb SS),
Haemoglobin SC disease (Hb SC), and Sickle Beta+ or 0
Thalassaemia (SB+ or 0 thal).
INHERITANCE
If both parents have the Sickle Cell trait or one has the Sickle Cell
trait and the other has another abnormal interacting haemoglobin trait,
there is a 1:4 chance at each pregnancy that the child will have a form of
Sickle Cell Disease. If one parent has Sickle Cell trait and the other a
form of Sickle Cell Disease, the risk is 1:2 at each pregnancy. The risks
are not affected by results of earlier pregnancy.
TYPES OF SICKLE CELL DISEASE
The most common type of sickle cell disease at birth
occurs when the Hb S gene is inherited from both parents causing
homozygous sickle cell disease (Hb SS). Other abnormal haemoglobin genes
inherited with Hb S may also cause sickle cell disease, these include Hb C
(common in West Africa), beta+ thalassaemia, and beta0
thalassaemia.
DISTRIBUTION
The Hb S gene is common in Africa but is not confined to people of
African ancestry, occurring widely around the Mediterranean, the Near East
and Central India. The common factor to this is a history of malaria.
CLINICAL PRESENTATION
PAIN
The subjective experience of pain is distressing at any
age and adults and children may have difficulties in coming to terms with
both the effects and unpredictability of pain crisis (Daniels
1990). Individuals need to know more about the kinds of activities
and situations that are likely to precipitate crisis. A significant
minority (around 20%) of adults with SCD experience frequent crises for
which hospitalisation is required (Williams et al, 1983),
whereas others are symptom free for long periods. In a study of acute
admissions in SCD, Brozovic, et al (1987) found that 6% of patients
accounted for over 40% of all admissions. Some individuals with apparent
SCD seldom experience episodes of severe pains and live to the 6th or 7th
decade as commented by Ruchnagel(1974). Most should be able to expect a
reasonable life expectancy and extended periods of good health. This would
depend on the level and quality of service available to them at present
and in the past, the relationship they have with their doctors, and their
attitudes and beliefs in relation to their condition and their ability to
manage it.
OTHER PROBLEMS
These include leg ulcers, priapism, and aspects of SCD relevant to
contraception and childbirth.
LEG ULCERS
Leg ulcerations are one of the less well understood complications of SCD.
It affects large numbers of older children and adults with SC anaemia in
the tropics (Chemolf, Shapleigh and Moore 1954).
It accounts for a good deal of pain, absence from work, decreased activity
and embarrassment. Leg ulcers are much less common in the UK and the USA,
and SC individuals are less severely affected (Koshy et
al. 1989). Leg ulcers are probably caused when minor cuts and
abrasions fail to heal normally because of poor blood flow in the affected
area. Treatment consists of careful cleaning and dressing over a period of
weeks or months, but there remains a high risk of recurrence
(Noel 1983). Ulcers are one of the few visible and
unsightly complications of SCD, increasing the potential for
stigmatisation in those affected and leading to embarrassment and
inhibition about dress and social activities.
PRIAPISM
It is a persistent and abnormal erection of the penis accompanied by
pain, tenderness and swelling. It may or may not be associated with sexual
arousal, but is not relieved by sexual activity (Hauri,
Spycher & Bruhlmann, 1983). Sickling causes priapism by
occluding the circulatory spaces and small blood vessels of the penis and
obstructing the drainage of blood from the corpora cavernosa
(Schmidt & Flocks 1971). Episodes can last for
days or weeks and can be among the most frightening and disturbing
complications of SCD. Prolonged episodes can lead to partial, or complete,
impotence. In extreme causes, exchange blood transfusion and even surgery
may be needed to drain blood from the penis to relieve engorgement and
pain. Early presentation and therapeutic intervention yield a successful
outcome (Bertram, Webster & Carson 1985).
FERTILITY (CONTRACEPTION
AND CHILDBIRTH)
Women and to a lesser extent, men with SCD are
potentially vulnerable to complications related to fertility,
contraception and childbirth. In males, lower semen volume, sperm count,
and sperm motility have all been observed (Davis 1988b),
which may relate to sickling in the testes. There is no evidence that
female fertility is affected by SCD, but pregnancy is potentially
problematic (see link on pregnancy).
CONTRACEPTION
Choices about contraception methods may be more difficult
for women with SCD because the coil may cause complications and the pill
can be dangerous (Serjeant 1983). This might be a
loss for women who prefer to be on the pill in order to control menstrual
difficulties, which are sometimes associated with SCD. Some women find
that their periods tend to set off painful sickling crisis.
