Clinical characteristics of headache in Italian adolescents aged 11–16 years: a cross-sectional questionnaire school-based study

Headache represents a common health problem in the pediatric age. By affecting daily activities, school performance and social relationships (i.e. with family and friends), headache can negatively impair quality of life, as well as physical and mental health. Several triggers and risk factors such as lifestyle, environment and psychological or psychiatric aspects can influence headache prevalence and frequency [1, 2]. Moreover, different comorbidities including behavioral problems, mood disorders (i.e. anxiety and depression), allergies, chronic diseases such as asthma and obesity, and sleep disorders can play a role in the pathophysiology of headache in childhood [2].

Numerous studies have assessed headache prevalence in children and adolescents in different geographic areas and settings (i.e. epidemiological population studies [3‐10] or clinical tertiary centers-based surveys [11, 12]). Headache in the pediatric population is variously reported, ranging between 2.8 and 91%, with a mean overall prevalence of 58.4% [13]. Many studies have highlighted an increasing incidence of primary headache and migraine among school-aged children in the last decades [14]. Furthermore, a gradual increase of headache prevalence during the transition from preschool to elementary school has been reported [15]. Headache prevalence reaches a peak in adolescence, acquiring the characteristic higher female-male ratio after this period [14]. Finally, chronic evolution into adulthood is possible: a longer time between headache onset and first medical consultation has been correlated with a worse outcome, stressing the importance of adequate diagnosis and management in young patients [16].

As emphasized by the Global Burden of Disease Study 2010 from the Institute of Health Metrics and Evaluation, population-based studies of headache disorders are important, as they inform needs assessment and underpin service policy for a disease that is a public-health priority [17]. Nevertheless, only few population-studies have tried to determine headache prevalence among adolescents in Italy in the past years [1, 3‐5, 11], the vast majority focusing on migraine or very selected populations from tertiary centers for headache management. The aim of this study was to fill this gap, by describing headache characteristics and impact on quality of life in a large group of Italian adolescents, with a detailed analysis of trigger factors, familiar and social co-factors, self-perceived pain evaluation, and medication attitudes.

Sixty-five percent of adolescents suffered from headache in our study population, with a female to male sex ratio of 1.25:1. Headache prevalence greatly varies among different studies in childhood, as it can be influenced by both methodological (i.e. 6-months, one-year or lifetime prevalence; population-based or clinical based studies; diagnostic and selection criteria) and demographic factors (i.e. age and sex distribution, socio-economic factors) [3, 6, 7, 9, 22, 23]. Similar lifetime prevalence and sex ratio have been reported in recent population-based studies on headache and migraine among adolescents [2, 8, 13, 14, 24‐26]. Population-based studies are known to detect a significantly higher prevalence of headache among adolescents: this is particularly true for those based on self-reporting questionnaires, as parents tend to underestimate the real burden of headache in this age group [13].

The age of symptoms onset in our study showed two peaks in peri-pubertal age, at 8 and 10 years, with a mean age at onset of about 8.3 years and an overall increase of headache onset with age (Fig. 1). This is in line with the results of recent Italian multicenter and single-center studies [3, 11], and several international publications showing an increment of the lifetime prevalence of headache from 47.2% in children 7–9 years old to 69.5% in those 13–15 years old [15, 27‐29]. Other studies have shown a later onset [7, 30], but this is probably attributable to different geographical and methodological factors. In their population-based study in Croatian adolescents, Cvetković and colleagues evidenced a significant older age at headache onset in girls with respect to male peers [7]. In our data, girls showed a moderate tendency for older age at onset without reaching statistical significance, possibly because of the small sample (only 220 students specified their age at onset in Group 1).

Genetic predisposition in headache and migraine is well documented [31, 32]. In the series by Kroner-Herwig et al., children of parents suffering from headache were also sufferers in 72% of cases, whereas in families where parents were headache-free only 27% of the children were diagnosed with headache [10]. In our study, a familiar predisposition was reported in 50.3% of students in Group 1, but this rate was significantly higher in females (54.3% vs 45.4%). Isense et al. suggest that in recognizing parental headache as a risk factor, not only genetic predisposition should be considered, but also the influence of dysfunctional pain-related modelling mechanisms: in this perspective, parental perception of and coping with headache may very soon influence the child’s cognitive, emotional and behavioral coping with pain, influencing intensity, frequency and pain-related disability [33].

Our results support recent findings that special consideration should be given to female adolescents [33, 34]. Other studies have revealed a higher incidence of headache as well as a higher burden, clinical heterogeneity and higher psychological comorbidity such as depression and anxiety in girls as compared to boys [6, 13, 33, 35]. However, this sex discrepancy seems to become relevant only from adolescence on [4, 6, 10, 36]. This study confirms a higher headache prevalence and intensity score in adolescent girls. Moreover, girls suffer significantly more often than boys during the school period and more frequently need to stop their activities in case of headache: this suggests a higher impact on their daily functioning and quality of life. Interestingly, girls seem more able than boys to identify trigger factors for headache exacerbations. 18.2% of girls identified menstruations as the major trigger in our study. Together with school issues and emotional stress, these accounted for 58.4% of all triggers in females. Finally, adolescent girls take more analgesics and recur to self-medication more frequently than male peers, while only 17.9% of them are treated following a physician’s advice. Analogous results have been reported in past studies [7, 30]. This findings may be essential to delineate better prevention strategies and underline the importance of promoting behavioral therapies, environmental hygiene and comorbidities management in adolescents with headache, particularly in girls. They also should rise physician’s awareness of the problem and encourage population screenings and timely adapted therapeutic approaches among health care professionals.

Several environmental factors are known to play a role in headache pathogenesis. Although the majority of subjects did not note seasonality changes in headache, winter was fairly the season most associated to headache exacerbations in those who did. In almost two thirds of the cases, headache occurs during school period and school/study represents the most common reported trigger factor in both sexes, followed by emotional stress. The literature reports a wide relationship between school issues and headache frequency, duration and intensity: notably, headache appears to be related to worries about performance, marks and promotions [3, 30].

Adolescents with migraine report significant impairment in health-related quality of life compared to non-migrainous peers, independently from psychiatric comorbidities [37]. The literature also reports numerous associations between headache frequency and severity, and several diverse physical complaints as well as physical and psychiatric morbidity later in life [10, 16, 38‐40]. This is particularly true for those children with high headache severity, who report the lowest quality of life, as well as the most issues regarding physical functioning, impact on daily and leisure activities and social functioning [41]. Furthermore, chronic conditions such as migraine are associated with a substantial burden on the cohabitating family members, who report a significant effect on family life and social activities [42]. Although we did not specifically consider psychiatric comorbidities in this study, our results suggest that more than half of the adolescents variably recognize an impact on daily activities during headaches attacks. Among those, nearly a half need to give up daily activities or seek for bed rest until the symptoms are over. Similarly, in a recent study assessing headache among adolescents in Croatia, 29.7% stayed at home and needed bed rest because of headache [7].

Headache during childhood has a high risk of persisting into adulthood [43]; it is therefore important to give adequate management to adolescents with recurrent and severe headaches. The majority (73.9%) of students suffering from headache takes medications for symptoms control: our data are in line with other studies, in which medication use is reported in a variable percentage going from 30% to 80% [3, 7, 30]. Nonetheless, only 16.7% reports systematical use of analgesics, while the majority waits until the intensity becomes moderate or high. While the larger part of adolescents ask their parents for medication advise, the percentage of those reporting self medication is considerable (5.7%). Overall, only the 20.6% declared to take medications following a physician’s prescription. This was reported respectively in 22.6 and 31.1% in different studies by Poyrazoglu [30] et al. and Kröner-Herwiget et al. [10], while it rises to 89% when taking into account specialized clinical settings based on tertiary centers for headache management [11]. Although it may be interpreted as a health behavior (relying on the child’s own capability to cope with the problem), the fact that the majority of students experiencing recurrent headache is treated without medical advice may underlie a parental underestimation of the headache burden. This may finally lead to undertreatment, or possibly encourage self-medication with the risk of misuse or abuse of painkillers [44].

Strengths of our study include the big sample-size and a low drop-out rate. Our study population was highly representative of the Italian adolescent population, as classes were randomly selected from secondary schools considering geographically and population-density data provided by the Italian Ministry of Education. A school-based population study eliminates the risk of selection-bias that is common in studies conducted in clinical settings. An anonymous, multiple-choice questionnaire allows a sincere and prejudice-less investigation in a by definition “fragile” population. Adolescents may frequently feel uncomfortable about talking about personal physical and psychological issues with medical or paramedical professionals: in this sense, an anonymous questionnaire may consistently minimize over- and under-estimations.

Our study has some limitations: 1) headache intensity and frequency was very heterogeneous in our study population, ranging from episodic attacks to chronic headache. 2) Headache was not classified following the ICHD criteria. This constitutes a major limit both for the lack of distinction between different types of primary headache, and between primary and secondary headache. Such classification requires validation by a trained specialist along with a throughout anamnestic investigation, and would not have been possible in the context of a self-evaluation questionnaire-based study. Moreover, it is difficult to categorize the type of headache in children because of the significant overlap of symptoms that meet both criteria for migraine without aura and tension-type headache, and this may frequently lead to misinterpretations [45]. A recent study by Balestri et al. underlined that classification of headache could be difficult considering duration criteria as a fundamental key [46], and Torriero et al. reaffirmed this statement suggesting that the exclusion of headache duration criteria allowed a diagnosis of primary headache in more than 80% of children in their study [47]. Furthermore, Ozge and colleagues recently commented on the necessary distinction between pediatric and adult headache, emphasizing that specific subtopics of pediatric headache should be carefully defined and included in next ICHD criteria [48]. 3) All questionnaire-based studies have intrinsic limitations, related to recall and interpretation biases. In this sense, students may have differently understood the questions and replied based on own interpretations with inadequate objectivity. Nevertheless, the questionnaire was completed under the supervision of a trained teacher, and students were encouraged to ask for advice and explanations to avoid misunderstandings. 4) Finally, no validated standardized questionnaire was given to determine quality of life, which was indirectly deduced from answers regarding impact on daily activities.

In this study we aimed to determine prevalence and characteristics of headache in a nation-wide representative sample of adolescents, a population which remains widely reported. Our results indicate that adolescence is at high risk for headache disorders, and support the need for more attention from health authorities and professionals: lifetime headache prevalence is high (reaching its peak in peri-pubertal age), underdiagnose and undermanagement are common and self-medication is frequent, while trigger factors are often easily detectable (thus targetable for specific primary and secondary prevention interventions). Adolescent girls, in particular, seem to carry the major medical and social disease burden. It is essential to offer adolescents who suffer from headache a timely psychological and medical management in order to implement quality of health and quality of life, and prevent chronic headache later in life.