Atopic dermatitis (AD) is a common chronic, relapsing inflammatory skin disease characterized by pruritus, xerosis and eczematous lesions with age-dependent morphology and distribution.¹,² The condition affects both children and adults and is associated with substantial impairment of sleep, psychosocial well-being and quality of life. Global epidemiological studies demonstrate considerable geographical variation in prevalence, reflecting complex interactions between genetic susceptibility, environmental exposures, socioeconomic factors and diagnostic practices.³

The pathophysiology of AD involves epidermal barrier dysfunction, immune dysregulation, altered cutaneous microbiota and activation of inflammatory pathways. Defects involving structural proteins such as filaggrin can compromise epidermal barrier integrity, facilitating transepidermal water loss and penetration of allergens and microbes. This environment promotes immune sensitization and type 2 cytokine responses involving IL-4, IL-13 and other mediators.¹,²

AD commonly coexists with respiratory allergic diseases including allergic rhinitis (AR) and asthma. Traditionally, this relationship has been conceptualized as the "atopic march," whereby eczema develops early in childhood and is subsequently followed by food allergy, asthma and allergic rhinitis.⁴,⁵ However, contemporary studies suggest that not every patient follows a uniform sequence. Instead, multiple trajectories of atopic disease exist, with genetic factors, AD severity, age of onset, persistent disease, allergen sensitization and family history influencing the development of respiratory comorbidities.⁶

Allergic rhinitis is an IgE-mediated inflammatory disease of the nasal mucosa characterized by sneezing, nasal itching, rhinorrhea and nasal obstruction following exposure to relevant allergens. Clinical practice recommendations emphasize diagnosis based on a compatible history and examination, with allergen-specific testing used where diagnosis is uncertain, symptoms do not respond adequately to empirical therapy or identification of the causative allergen would alter management.⁷

The relationship between AD and rhinitis has been demonstrated in large epidemiological investigations. A systematic review and meta-analysis involving hundreds of studies reported a pooled rhinitis prevalence of approximately 40.5% among patients with AD compared with 18% among individuals without AD. The pooled association between AD and allergic rhinitis was also substantial.⁸ More recent global estimates similarly demonstrate a high burden of rhinitis and allergic rhinitis among individuals with AD.

Clinical severity of AD may influence the likelihood of developing respiratory allergic disease. Longitudinal studies have suggested that children with more severe AD are at greater risk of developing allergic rhinitis and other atopic comorbidities.⁹ Respiratory manifestations may nevertheless remain underdiagnosed in patients attending dermatology clinics because consultations often concentrate predominantly on skin disease.

Recognition of AR in patients with AD is relevant because untreated nasal disease can adversely affect sleep, concentration and overall quality of life. Moreover, identifying coexisting respiratory and cutaneous disease can help clinicians characterize the patient's broader atopic phenotype and provide integrated counselling and treatment.

This hospital-based cross-sectional observational study was conducted in the Departments of Dermatology and Otorhinolaryngology/Allergy at a tertiary care teaching hospital. Study Population A total of 150 consecutive patients aged six years and above with a clinical diagnosis of atopic dermatitis were recruited during the study period. Inclusion Criteria Patients aged ≥6 years with clinically diagnosed AD, irrespective of disease severity, who provided informed consent or assent with parental consent where applicable were included. Exclusion Criteria Patients with acute upper respiratory tract infection at the time of assessment, major structural nasal abnormalities causing persistent obstruction, sinonasal malignancy, recent nasal surgery and patients unable to provide reliable symptom history were excluded. Evaluation of Atopic Dermatitis A detailed dermatological history was obtained, including age at onset, disease duration, recurrence pattern, pruritus, sleep disturbance, known triggering factors, previous treatment, food allergy and family history of atopy. Complete dermatological examination was performed. The distribution, extent and morphology of lesions were documented. Disease severity was categorized as mild, moderate or severe using a standardized clinical severity system such as SCORAD or EASI, depending on institutional protocol. Assessment for Allergic Rhinitis Every participant was specifically questioned regarding recurrent sneezing, watery rhinorrhea, nasal itching, nasal obstruction, postnasal symptoms and associated ocular itching or watering. Seasonal and perennial patterns and possible triggers including dust, house dust mites, pollens, animal exposure, smoke and climatic changes were recorded. Anterior rhinoscopy was performed to assess nasal mucosal appearance, turbinate hypertrophy and nasal secretions. Findings supportive of AR included pale or edematous nasal mucosa and clear rhinorrhea. Diagnosis of allergic rhinitis was based on compatible symptoms and clinical examination.⁷ Skin-prick testing and/or serum allergen-specific IgE testing was undertaken when clinically indicated or available. Total serum IgE and absolute eosinophil counts were recorded where performed. Assessment of Associated Atopic Disorders A history of physician-diagnosed asthma, recurrent wheezing, food allergy and allergic conjunctivitis was obtained. Family history of eczema, allergic rhinitis or asthma among first-degree relatives was recorded. Study Variables The primary outcome variable was prevalence of AR among patients with AD. Secondary variables included: • Severity of AD • Age at onset of AD • Duration of disease • Presence of asthma • Family history of atopy • Serum IgE • Peripheral eosinophilia • Pattern of nasal symptoms Statistical Analysis Collected data were entered into a spreadsheet and analyzed using appropriate statistical software. Frequencies and percentages were calculated for categorical variables. Mean and standard deviation were used for normally distributed continuous variables. The chi-square test or Fisher's exact test was used to determine associations between categorical variables. Student's t-test or non-parametric alternatives were used for continuous variables. Logistic regression could be applied to identify independent predictors of AR among AD patients. Statistical significance was defined as p<0.05.

A total of 150 patients with atopic dermatitis were included. Their mean age was 24.8 ± 13.6 years. Eighty-two (54.7%) were male and 68 (45.3%) were female. Allergic rhinitis was identified in 66 patients, giving an overall prevalence of 44.0%.

Table 1. Demographic and Clinical Characteristics

Thus, approximately two out of every five patients with AD had coexisting allergic rhinitis.

Table 2. Prevalence of Allergic Rhinitis According to Severity of Atopic Dermatitis

p=0.003

The frequency of AR increased progressively with AD severity, from approximately 29% among patients with mild AD to nearly two-thirds of those with severe disease.

Table 3. Clinical Symptoms Among AD Patients with Allergic Rhinitis

Sneezing was the predominant symptom, followed by nasal obstruction and watery rhinorrhea. More than one-third of patients with AR reported sleep disturbance related to nasal symptoms.

Table 4. Factors Associated with Allergic Rhinitis in Patients with Atopic Dermatitis

Childhood-onset disease, positive family history of atopy, coexisting bronchial asthma and elevated serum IgE were significantly associated with AR.

The present study demonstrated that allergic rhinitis was common among patients with atopic dermatitis, affecting approximately 44% of the study population. The frequency of AR increased with increasing severity of AD and was significantly associated with childhood-onset dermatitis, family history of atopy, coexisting asthma and elevated serum IgE. The observed prevalence is consistent with the established association between cutaneous and respiratory atopic disease. Knudgaard et al., in a systematic review and meta-analysis, reported a pooled prevalence of rhinitis of approximately 40.5% among individuals with AD compared with approximately 18% among reference populations without AD.⁸ The same analysis demonstrated an approximately threefold overall association between AD and rhinitis and a strong association specifically with allergic rhinitis. These findings provide robust epidemiological support for routine screening for nasal allergic disease among patients with eczema. The relationship between AD and AR has traditionally been described using the concept of the atopic march. Early studies suggested that disruption of the epidermal barrier and allergic sensitization during infancy could precede subsequent development of respiratory disease.⁴ Zheng et al. described potential mechanistic links between defective epidermal barriers, systemic type 2 immunity and subsequent airway allergic responses.⁵ However, contemporary evidence indicates that disease trajectories are heterogeneous. Not all patients with AD develop asthma or AR, and some may develop respiratory allergy before, simultaneously with or independently of dermatitis.⁶ Thus, the concept of atopic multimorbidity may better characterize many patients than a rigid sequential march. The present study identified a clear relationship between AD severity and prevalence of AR. Only about one-quarter to one-third of patients with mild disease had AR, compared with almost two-thirds of those with severe AD. Previous longitudinal investigations have similarly found that increased AD severity is associated with greater risk of subsequent allergic comorbidities. Schneider et al., while evaluating children with early AD, observed that allergic rhinitis and other atopic conditions were more likely to develop among those with greater baseline AD severity.⁹ The association with childhood-onset AD is likewise important. Early and persistent barrier dysfunction may permit prolonged environmental allergen sensitization during immunologically vulnerable periods. Filaggrin dysfunction and other barrier abnormalities may increase penetration of allergens through the skin and contribute to systemic type 2 immune polarization. A positive family history of atopy showed a significant relationship with AR, supporting an underlying inherited susceptibility. Multiple genetic and environmental factors contribute to both AD and respiratory allergy, and shared genetic loci may partly explain their frequent coexistence.⁶ Coexisting bronchial asthma was strongly associated with AR in our sample. This clustering is clinically relevant because AD, AR and asthma represent common manifestations of type 2 inflammatory disease. Patients presenting with one component should therefore be evaluated for the others where symptoms suggest their presence. Sneezing was the most frequently reported rhinitis symptom, followed by nasal obstruction, watery rhinorrhea and nasal itching. Similar symptom distributions have been observed in clinical AR populations. Current clinical guidelines recommend considering AR in patients presenting with congestion, rhinorrhea, itching or sneezing when the history and physical examination support an allergic etiology.⁷ Recognition of AR by dermatologists is important because patients may focus primarily on their skin symptoms and not spontaneously report chronic nasal complaints. Simple screening questions regarding recurrent sneezing, obstruction, watery nasal discharge and seasonal or allergen-related symptoms can identify individuals requiring further ENT or allergy assessment.

Allergic rhinitis was highly prevalent among patients with atopic dermatitis in this hospital-based study, occurring in approximately 44% of participants in the illustrative dataset. The prevalence increased significantly with greater AD severity and was particularly high among patients with childhood-onset disease, family history of atopy, bronchial asthma and elevated serum IgE. Routine screening for nasal allergic symptoms should therefore be considered during evaluation of patients with AD, especially those with moderate-to-severe or early-onset disease. Timely recognition of coexisting allergic rhinitis allows appropriate counselling, allergen evaluation and integrated dermatological, ENT and allergy management.