INTRODUCTION

Acne vulgaris is among the most prevalent dermatological conditions globally, affecting approximately 9–10% of the population [1–5]. Traditionally considered an adolescent disorder, there is increasing recognition that acne frequently persists into adulthood or presents de novo later in life [6–8]. The disease encompasses a spectrum of lesions, including comedones, papules, pustules, nodules, and cysts, forming the basis of clinical severity grading systems such as the Investigator Global Assessment (IGA) [9–11].

Beyond its cutaneous manifestations, acne is associated with significant physical and psychosocial morbidity. Complications such as scarring and post-inflammatory hyperpigmentation (PIH) can lead to long-term cosmetic and psychological consequences [12–14]. In addition, acne has been linked to a range of comorbidities, including inflammatory dermatoses, metabolic disorders, and psychiatric conditions, highlighting its multifactorial nature [15–23].

Despite extensive global research, rural populations particularly in sub-Saharan Africa remain underrepresented. Limited access to healthcare, delayed presentation, and differences in skin type may influence disease severity and outcomes. This study aims to address this gap by characterising acne severity, complications, and comorbidity patterns in a rural tertiary dermatology setting in South Africa.

MATERIALS AND METHODS

RESULTS

All participants were African (100%), reflecting the rural catchment population. Adult-onset acne (>18 years) was 85.5%, adolescent onset 13.3%, childhood onset: 1.2%, while recurrent disease was reported in 53.0% of patients.

Comorbidities were documented in 52.4% of patients. The prevalence varied descriptively across acne phenotypes, being highest in acne excoriée (71.4%), followed by steroid-induced acne (66.7%), acne vulgaris (53.6%), and nodulocystic acne (41.7%); conversely, absence of comorbidity was most frequent in nodulocystic acne (58.3%). However, overall comorbidity status was not significantly associated with acne phenotype (p > 0.05; Table 1).

Table 1: Association between acne subtypes and demographic, environmental, geographic, and clinical variables.

The spectrum of comorbidities also varied across acne phenotypes (Table 2). Eczema was most frequently observed in acne vulgaris (58.1%), compared with steroid-induced acne (25.0%) and nodulocystic acne (20.0%). Melasma was proportionally most frequent in acne excoriée (60.0%) and nodulocystic acne (30.0%), compared with acne vulgaris (10.8%) and steroid-induced acne (8.3%). Other documented comorbidities were less frequent and occurred predominantly among patients with acne vulgaris. The table below presents the predominant Adult-onset acne, recurrence was reported in 53.0% of patients, and moderate acne was the most common severity category. Papules and comedones were the predominant lesions, while post-inflammatory hyperpigmentation was the most frequent complication (Table 3).

	Table 2: Distribution of dermatologic and systemic comorbidities across acne subtypes.
	Table 3: Disease onset, severity grading, lesion distribution, and complications in the study cohort of 166 participants.

Figure 1 shows that 52.4% of patients had at least one documented comorbidity, compared with 47.6% with no comorbidity, indicating a substantial comorbidity burden. Overall, more than one in two patients with acne had a coexisting condition, underscoring the clinical complexity of acne in this rural tertiary cohort (Fig. 1).

Figure 1: Monomorphic comedonal eruption in a patient with steroid-induced acne.

Figure 2 demonstrates variation in comorbidity burden across acne phenotypes, highest in acne excoriée (71.4%) and steroid-induced acne (66.7%), followed by acne vulgaris (53.6%) and nodulocystic acne (41.7%). Despite these numerical differences, overall comorbidity prevalence did not differ significantly by acne phenotype (p > 0.05) (Fig. 2).

Figure 2: Distribution of comorbidities according to acne phenotype.

DISCUSSION

This study provides original clinical evidence on the presentation, severity, complications, and comorbidity patterns of acne among patients attending a rural tertiary dermatology service in South Africa. The principal findings were the predominance of adult-onset and recurrent acne, a mainly moderate disease profile, extensive facial involvement, a high burden of post-inflammatory hyperpigmentation (PIH), and considerable dermatological comorbidity. These findings are clinically important because rural African populations remain underrepresented in acne research, despite differences in skin phototype, access to specialist dermatological services, treatment-seeking behaviour, and the risk of pigmentary sequelae.

Adult-onset acne accounted for 85.5% of cases, whereas adolescent- and childhood-onset acne were comparatively uncommon. This differs from the traditional perception of acne as predominantly an adolescent disorder but supports growing evidence that acne may persist into or first present during adulthood [24–26]. Studies from other settings have similarly documented a substantial burden of post-adolescent acne, particularly among women [6–8,24–26]. The high proportion observed in the present study may also reflect the tertiary referral setting, where adults with persistent, recurrent, treatment-resistant, or complicated acne are more likely to be referred than adolescents with mild disease. Delayed presentation and limited access to dermatology services in rural areas may further contribute to the accumulation of adult cases.

More than half of the participants experienced recurrent disease, demonstrating the chronic and relapsing nature of acne in this population. Recurrence may be associated with premature treatment discontinuation, inadequate maintenance therapy, limited access to appropriate topical treatments, hormonal influences, or the use of inappropriate skin products. Although treatment adherence and previous therapeutic regimens could not be comprehensively evaluated from the available records, the observed recurrence emphasises the need for long-term management plans, patient education, maintenance therapy, and scheduled follow-up rather than short-term treatment of active lesions alone.

Moderate acne was the most common severity category, followed by mild and severe disease. The predominance of moderate disease may reflect referral patterns and delayed access to specialist care. Papules and comedones were the most frequent lesions, while facial involvement was almost universal. Facial acne has particular clinical importance because visible lesions and residual pigmentary changes may adversely affect self-image, social interaction, and psychological well-being [15–17]. Although psychosocial outcomes were not routinely documented in the medical records, previous studies have demonstrated associations between acne, social appearance anxiety, stigma, depression, and reduced quality of life [16–18]. Future studies in this setting should therefore include validated measures of acne-related quality of life and psychological distress.

The very high prevalence of PIH was one of the most important findings. PIH occurred considerably more frequently than either atrophic or keloidal scarring. This pattern is consistent with evidence showing that individuals with darker skin phototypes are particularly susceptible to persistent pigmentary alteration following cutaneous inflammation [12–14,27,28]. In patients with skin of colour, PIH may remain visible long after active acne lesions have resolved and may sometimes be more distressing than the acne itself. Persistent inflammation, delayed initiation of effective therapy, manipulation of lesions, inappropriate use of topical products, and inadequate photoprotection may contribute to its development. These findings support early control of inflammation and the incorporation of PIH prevention and treatment into routine acne management.

Atrophic scarring affected approximately one-quarter of the cohort, whereas keloidal scarring was less frequent. Scarring represents irreversible structural damage and is generally associated with prolonged inflammation, severe lesions, delayed treatment, and recurrent disease. The simultaneous occurrence of PIH and scarring demonstrates that clinical evaluation should extend beyond counting active lesions. In rural tertiary settings, acne management should include early assessment of the risk of pigmentary change and permanent scarring, together with timely escalation of therapy where indicated.

Comorbidities were documented in more than half of the participants, although their distribution varied across acne phenotypes. Eczema was common among patients with acne vulgaris, while melasma was proportionally more frequent in acne excoriée and nodulocystic acne. The coexistence of acne and eczema may reflect shared abnormalities in epidermal barrier function, cutaneous inflammation, environmental exposures, or the effects of skincare practices [19,29,30]. The relationship between acne and melasma may also be influenced by sex, hormonal factors, ultraviolet exposure, and the use of cosmetic or skin-lightening products. Nevertheless, some acne subtypes contained relatively few patients; consequently, proportional differences should be interpreted cautiously.

No statistically significant associations were observed between acne subtype and demographic, seasonal, climatic, geographical, or clinical variables. This finding does not necessarily indicate that these factors have no influence on acne. The absence of significant associations may reflect limited statistical power within the smaller subtype categories, relatively homogeneous environmental exposure within the rural catchment population, or incomplete documentation inherent in retrospective records. Furthermore, acne is multifactorial and may be influenced by hormonal status, genetics, diet, stress, cosmetic practices, medication exposure, and treatment history—variables that were not consistently available. The findings should therefore be interpreted as indicating that no associations were demonstrated in this cohort rather than confirming the absence of such relationships.

The study has several clinical and service-delivery implications. Rural healthcare providers should be trained to recognise acne early, assess severity using a standardised grading system, and identify patients at risk of PIH and scarring. Referral pathways should prioritise patients with nodulocystic disease, recurrent acne, progressive scarring, or substantial pigmentary complications. Treatment guidelines for patients with skin of colour should address both active acne and its pigmentary consequences. Improved availability of appropriate topical therapies, patient counselling, avoidance of harmful skin products, and continuity of care may reduce long-term complications.

The strengths of this study include census sampling of eligible cases, dermatologist-confirmed diagnoses, use of the validated Investigator Global Assessment scale, and the inclusion of real-world clinical data from an understudied rural African population. However, the retrospective design limits causal interpretation and depends on the completeness of medical records. Psychosocial outcomes, treatment adherence, hormonal factors, dietary exposures, cosmetic practices, and previous treatment were not consistently recorded. Small numbers in some acne subtype categories may have limited the ability to detect statistically significant associations. The single-centre tertiary setting may also limit generalisability and may overrepresent persistent or complicated cases. Future prospective multicentre studies should include primary and secondary healthcare facilities, validated quality-of-life instruments, detailed treatment histories, skin-phototype assessment, and multivariable analyses of factors associated with recurrence, PIH, and scarring.

CONCLUSION

Acne in this rural tertiary population is characterised by predominantly adult onset, Frequent recurrence, moderate severity, high prevalence of pigmentary complications These findings underscore the need for context-specific, early, and comprehensive management strategies in underserved populations.