Dermatopathology is the branch of pathology dedicated to diagnosing skin disorders based on their microscopic and clinical characteristics [1]. Immunohistochemistry (IHC) plays a vital role in this field by enhancing diagnostic accuracy, thereby indirectly informing patient management decisions for various skin disorders. While haematoxylin and eosin (H&E) staining is the standard for histological assessment, it can fall short when lesions have non-specific or similar histological appearances, underscoring the need for supplementary diagnostic methods [2]. In this context, IHC serves as a valuable adjunct by enabling the detection of specific proteins or molecular markers within tissue samples. By highlighting how specific proteins are expressed across different cell types, IHC helps trace cellular origins and developmental pathways that remain obscure under standard staining, thereby improving diagnostic confidence [3]. Such diagnostic precision is important because it can influence therapy selection, prognosis estimation and long-term patient management. As pathologists encounter increasingly complex cases with overlapping clinical and microscopic features, IHC serves as a powerful tool to reduce uncertainty and ultimately improve patient outcomes. Its integration into routine diagnostic workflows marks a major advance in the field, highlighting the growing importance of combining morphological assessment with molecular profiling to achieve accurate clinical results.

Precise histopathological evaluation of skin diseases remains challenging due to the considerable overlap in both clinical presentation and microscopic characteristics. Numerous dermatological disorders display comparable inflammation patterns and tissue architecture, complicating the differentiation between benign, malignant, infectious, or autoimmune conditions when relying solely on conventional histological techniques [4]. This diagnostic uncertainty can lead to misclassification, potentially resulting in inappropriate or delayed treatment. For example, inflammatory skin conditions may sometimes resemble early-stage neoplasms, while some malignancies may resemble benign lesions, creating a diagnostic grey zone that requires additional investigative tools [5]. IHC addresses these challenges by adding molecular specificity to histological interpretation. By targeting molecular markers that are selectively expressed in particular cell types or disease states, IHC enables the detection of molecular-level differences that are not apparent with conventional histology. This is particularly useful in complex cases where traditional methods yield inconclusive or contradictory findings. Furthermore, IHC can help resolve diagnostic ambiguity in cases with overlapping inflammatory and neoplastic features, which are difficult to distinguish morphologically. In doing so, IHC facilitates more accurate, timely and clinically relevant interventions. IHC serves as a molecular bridge, linking the outward appearance of skin lesions to their underlying biological activity, ensuring that patient management decisions are based on the most accurate and specific information available [6].

The application of IHC in dermatopathology extends beyond diagnosis. It also has profound implications for patient management and prognosis. Accurate pathological classification of skin diseases supports clinicians in making informed, individualised treatment decisions. For instance, distinguishing between different types of skin tumours or inflammatory conditions allows for treatment plans tailored to the specific biology of the disease, which can improve efficacy and reduce unnecessary interventions [7]. In selected cases, IHC can reveal patterns of protein expression that correlate with tumour aggressiveness, immune response or potential responsiveness to targeted therapies. Such insights can guide decisions about surgery, medical therapies or immunotherapy [8]. Moreover, resolving diagnostic uncertainty with IHC helps prevent excessive treatment of harmless conditions and ensures adequate care for more serious pathologies. Beyond treatment selection, IHC can provide prognostic indicators by highlighting factors that correlate with disease progression or recurrence risk. This prognostic information helps clinicians counsel patients more effectively and plan appropriate follow-up. The integration of IHC into clinical practice links molecular characteristics with care pathways. As a result, patients receive more informed and precise treatments, which ultimately leads to better clinical outcomes and improved quality of life [9].

While IHC offers significant diagnostic advantages, its clinical implementation is not without challenges. Differences in sample preparation, antibody choice, and staining protocols can influence the reliability and clarity of IHC results [10]. These variables may result in weak or nonspecific staining, complicating diagnostic interpretation. Moreover, the evaluation of IHC slides requires significant expertise. Distinguishing genuine marker expression from background staining or artefacts requires significant interpretive skill. Without proper experience and rigorous quality control, there is a risk of misinterpretation, which can undermine the benefits of this technique [11]. IHC also demands considerable resources. Reliable interpretation depends on factors such as specialised instruments, high-quality reagents and skilled laboratory staff, all of which may be limited in certain healthcare settings [12]. These constraints highlight the importance of standardised protocols, ongoing training, education and investment in infrastructure to fully realise the clinical utility of IHC. Emerging solutions, such as automation and digital workflow integration, hold promise for minimising variability and expanding access, although expert oversight will remain essential to ensure clarity in diagnosis.

Looking ahead, advancements in technology are poised to expand the role and impact of IHC in dermatopathology. Innovations such as multiplex IHC enable several markers to be visualised on the same sample, offering a deeper diagnostic view while conserving tissue. This approach enables a more comprehensive analysis and can reveal complex interactions within the tissue microenvironment that inform diagnosis and prognosis [13]. At the same time, digital pathology and artificial intelligence (AI) technologies are reshaping IHC interpretation through advanced image analysis techniques. AI algorithms may quantitatively analyse staining patterns and highlight diagnostically relevant features that might otherwise be missed [14]. AI-assisted tools offer promise in refining diagnostic precision and expediting slide analysis by enhancing pattern recognition and reducing human variability. Furthermore, advances in automation and standardised protocols may lower costs and increase accessibility, bringing the benefits of IHC to a broader range of clinical settings [15]. As these tools become more widely adopted, IHC is likely to evolve into an even more powerful component of dermatopathological diagnostics, offering faster, more reliable and more nuanced assessments.

IHC has become the cornerstone of modern dermatopathology, significantly enhancing diagnostic precision and clinical relevance. IHC bridges histological appearance and molecular data, reducing diagnostic uncertainty and guiding both treatment and prognosis. Its growing role in medicine reflects the increasing complexity of dermatological disease and the demand for targeted data-driven care. Although technical and logistical challenges persist, rapid innovation is improving the accessibility, consistency and utility of IHC. As new technologies and digital tools are incorporated into routine practice, IHC is set to become even more integral to dermatopathological evaluation, empowering pathologists to deliver more precise, timely, and personalised insights, ultimately advancing the quality and effectiveness of dermatological care.

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