Nig. J. Child Adol. Health Vol 3, No 2 Dec, 2020 |Olajide et al., (29-39)
Keloid in Nigeria: More questions than answers
ABSTRACT
Taiwo H. Olajide,
Oluwayemi J. Bamikole, Nigeria reported an estimated incidence of 1.5 million in the
Subulade A Ademola, year 2017 making it one of the highest reasons for
Olukemi K. Amodu dermatology and plastic surgery consults in Nigeria to date.
Institute of Child Health, College of Medicine, The current available prevalence does not represent the true
University of Ibadan, Nigeria prevalence of the condition as majority of the keloid affected
individuals (Keloid formers) either resort to unorthodox/
traditional therapies while majority do not seek therapy at
all. Several hypotheses have been propounded for the
pathogenesis of Keloids with no clear definition of the
development of the condition. As with its pathogenesis, a
definite inheritance pattern has not been established for
Keloids. Results from genome wide association studies in
different populations have yielded different results of
Correspondence:
Taiwo H. Olajide, Public Health Biotechnology possible candidate loci.
Program, Institute of Child Health, College of
Although very common in Nigeria, its awareness within the
Medicine, University of Ibadan
olajidetaiwo15@yahoo.com population is still very low with several prevailing beliefs
about the causes of Keloids within the population. However,
majority of these beliefs are wrong. The erroneous beliefs about Keloids among Nigerians most importantly the
cosmetic deformity associated with it have contributed negatively to the wellbeing of keloid formers hence making
the condition a source of psychological trauma for them.
Here we highlight the current situation of keloids within the Nigerian populace to raise pertinent questions. This will
help to ultimately chart a new course for the awareness, acquire a better understanding of the pathogenesis, genetics
and socio-cultural factors associated with Keloids among Nigerians.
Keywords: Keloid, Pathogenesis, Cosmetic, Trauma, Genetics
INTRODUCTION precipitate it. Keloid develop within three months to a
year after the wound healing(Robles & Berg, 2007).
The term Keloid, derived from the Greek word ‘chele’,
Although not fatal, Keloids present with a range of
meaning crab’s claw was first used in 1806 by Alibert
morbidities such as pain, erythema, itchiness, cosmetic
to describe cutaneous fibrosis because of their
unsightliness, and functional impairments (Devika &
distinguishing processes (Louw, 2000). Keloids are
Arockiamary, 2011). Keloids constitutes a source of
excessive scar tissues that grow beyond the margin of
emotional and psychological trauma to affected
the original wound. They are a form of pseudo-
individuals clinically referred to as keloid
malignant growth which develops sequel to the wound
formers(Olasode, 2010). Based on the mode of
healing process in genetically predisposed individuals
occurrence, Keloids can be classified as primary or
(Bienias, Miȩkoś-Zydek, & Kaszuba, 2011). Keloid
spontaneous when they occur idiopathically or
scars otherwise known as cutaneous fibrosis, are
secondary when they occur as a consequence of a
distinguishable from other raised scars by having
trauma to the skin. Primary Keloids are thought to
claw-like erythematous processes (Janssen de
account for as much a third of all cases (Olabanji &
Limpens & Cormane, 1982). Keloid presents as
Oladele, 2011). Keloids affect all age groups however,
smooth, globular, shiny swellings having the same
they reach peak incidence between the second and
color as that of the surrounding skin of the wounds that
fourth decade of life (Salami & E Irekpita, 2011).
1
, Nig. J. Child Adol. Health Vol 3, No 2 Dec, 2020 |Olajide et al., (29-39)
PREVALENCE OF KELOIDS 2016). This hypothesis is supported with the world
prevalence figures with African having the highest
Keloids are predominantly found among dark skinned
prevalence followed by Hispanics, Asians and
individuals and this prevalence seems to follow the
Caucasians. Studies have revealed the increased
skin color gradient with Blacks having the highest
tendency of Keloids to develop in area of the body
observed prevalence followed by Hispanics, Asians
where there is higher concentration of melanocytes
and the least prevalence among Caucasians (Trace,
(Wolfram et al., 2009). The postulation of melanin as
Enos, Mantel, & Harvey, 2016). An estimated 427,000
a risk factor is being questioned with the reports of
physician visits in the United States per year can be
Keloids among albinos (Kiprono et al., 2015).
attributed to Keloids with African Americans making
up the bulk of this population (Hahn, McFarland, C, Genetics. Keloids have long been associated with
& M., 2016). A prevalence of 0.09% was reported genetics with the disease having been established to
among Caucasians of European origin (Brown & segregate within families(Santos-Cortez et al., 2017).
Bayat, 2009) with about 6%, 3.5% and 16% of Individuals with a positive family history of Keloids
individuals of west African origin (Henshaw et al., are at four times higher risk of developing Keloids and
2015), east African population(Kiprono et al., 2015) eight times more likely to develop keloids at multiple
and Central African population respectively being sites, suggesting a strong genetic underpinning factor
keloid formers (Kouotou et al., 2019). Over 1.5 in the occurrence of Keloids (Belie, Ugburo, &
million Nigerians are thought to be Keloid formers in Mofikoya, 2019). Although recently reported to be a
the year 2017, with about 36% of this figure accounted polygenic and heterogeneous disease condition (Glass,
for by familial cases (Olaitan, 2009). Keloids is 2017), studies around the world have established
significantly more frequent in the southern part of the mendelian inheritance patterns for Keloids (Devika &
country as compared to the north although the reason Arockiamary, 2011). It was established to be inherited
for this disparity remains to be proven (Henshaw et al., through the autosomal recessive pattern in the
2018). Nigerian population (Omo Dare, 1975). However, this
inheritance pattern has not been successfully
RISK FACTORS
replicated in Nigeria nor any other population where
Several attempts have been made to define the factors keloids are prevalent. Bloom,1956 who studied five
that predisposes an individual to the development of Italian family pedigrees concluded that keloids are
Keloids. These efforts have identified factors such as inherited in an autosomal dominant fashion although
Melanin, Genetics, Age, Body Mass Index, Insulin- the expression varies among individuals. This
like Growth factor among others(Wolfram, Tzankov, assertion was corroborated by the report of (Marneros
Pülzl, & Piza-Katzer, 2009). These factors have been et al., 2001) who in their study of fourteen families
demonstrated to be associated with the condition at the from diverse ancestral backgrounds including African-
epidemiological level, however, further studies aimed Americans. Genome wide association studies have
at utilizing these factors to describe the pathogenesis recently established Keloids to be associated with
of Keloid have been largely inconclusive. multiple loci however there have been varying degrees
of replicability in the results from different
Melanin. The hormone responsible for the populations thus suggesting the involvement of
pigmentation of the skin has been associated with underlying factors ( Lu et al., 2018). A GWAS study
Keloids (Dyal, 1989). Prevalence figures showed that among the Japanese population showed that SNPs
darker individuals are more predisposed to rs873549, rs1511412, rs8032158 were associated
development of the disease (Brown & Bayat, 2009) . keloid development(Nakashima et al., 2010). Three
This association appears to be dose dependent with SNPs (rs1511412, rs940187 rs2271289) and
prevalence higher in dark skinned individuals than rs35641839 were associated with keloids among the
light skinned population implying an inversely Chinese Han population and African- Americans
proportional relationship between keloid prevalence respectively (Lu et al., 2018;Velez et al., 2014). The
and the quantity or presence of melanin pigment almost non-presence of overlaps of the associated
(Andrews, Marttala, Macarak, Rosenbloom, & Uitto, SNPs is suggestive the heterogeneity of keloids. The
2
