Phenotypic Dermatology: Conceptual and Cytometric Foundations

For decades, the development of dermatology has relied predominantly on morphological observation and clinical interpretation of symptoms. However, the growing understanding of the skin as an active immune organ, together with advances in modern technologies, has enabled investigation of the cellular mechanisms underlying clinical manifestations, thereby bringing dermatology closer to the level of precision medicine.

The present work substantiates a transition from morphological description of skin conditions to phenotypic analysis of its cellular subpopulations. It is demonstrated that the phenotype of skin-cell subpopulations may be regarded as a conceptual “unit” for explaining the diversity of skin states. This approach eliminates the gap between observable symptoms and the underlying cellular processes.

The resolution of this problem became possible through the development and patenting of methods for obtaining viable heterogeneous populations of skin cells and determining their subpopulation composition with the construction of a skin cytoimmunogram. For the first time, a method has been established for the in vivo quantitative and functional assessment of cells within the local immune compartment of the skin. This has opened the way for monitoring the dynamics of cellular phenotypes in both physiological and pathological conditions and has laid the foundation for precision diagnostics of immune-mediated dermatoses.

Experimental studies confirmed that changes in the phenotypes of cellular subpopulations can be instrumentally registered and correlate with clinical manifestations of disease and wound-healing processes. It has been established that quantitative alterations in cell-surface molecules reflect membrane events leading to the formation of morphological elements of the rash. Thus, a direct relationship between the cellular level of skin organization and its clinical manifestations has been demonstrated for the first time.

On the basis of these findings, the biotechnological agent Cellgel was developed and implemented. Its mechanism of action is associated with selective activation of cells expressing the CD34⁺ CD45^dim phenotype. Experimental studies have demonstrated its reparative, proliferative, and bacteriostatic effects, as well as its safety profile. Methods for its production, protocols for the treatment of wounds of various etiologies, and technical specifications for serial manufacturing have been developed. Practical implementation of this solution has been confirmed by patents, laboratory testing protocols, and industrial deployment.

In addition, a utility model device designed for selective activation of the reparative potential of skin cells—an amplifier—has been developed, opening prospects for targeted modulation of phenotypically distinct cellular subpopulations. This demonstrates the feasibility of controlled modulation of skin-cell states.

The synthesis of methods from experimental dermatology, immunology, and conceptual analysis enabled the formation of a systemic model of the phenotypic diversity of skin cells. Conceptualization revealed classes of potential states previously indistinguishable within dermatology and created a foundation for the development of new research programs.

The principal results of this work may be summarized as follows:

– substantiation of the use of skin-cell subpopulation phenotypes as a conceptual unit for analyzing skin states;
– development of a modeling framework for phenotypic diversity of skin cells based on the synthesis of experimental and conceptual methodologies;
– experimental confirmation of the feasibility of quantitative and functional assessment of viable skin cells by flow cytometry;
– development and patenting of methods for obtaining viable heterogeneous populations of skin cells and determining their subpopulation composition with construction of a skin cytoimmunogram;
– creation of a diagnostic marker panel enabling precision assessment of the dynamics of cellular subpopulation states;
– development of the biotechnological agent Cellgel, its method of production, and therapeutic protocols for wounds of various etiologies;
– development of a utility model amplifier for selective activation of reparative cellular potential in vitro;
– demonstration of the productivity of interdisciplinary synthesis as a methodological basis for the further development of dermatology.

The principal outcome of this work lies in the fact that dermatology has, for the first time, acquired an instrumental means of resolving the contradiction between observable clinical manifestations and the cellular mechanisms underlying their formation. Dermatology thus gains the capacity to operate not only with symptoms but with quantifiable characteristics of skin states. The transition from symptomatic to phenotypic analysis opens the possibility of predicting pathological processes and exerting controlled influence upon them.

This transition represents not merely the introduction of a new method but a transformation in the level of disciplinary understanding—from description of external manifestations to calculation and prediction of skin states based on instrumentally measurable phenotypes of its cellular subpopulations.

Phenotypic dermatology is thus emerging as a new type of discipline—one that integrates theory and practice and is capable of operating with measurable characteristics of cellular skin states while incorporating experimental data into clinical decision-making.

CONCISE CONCLUSIONS AND RESEARCH PERSPECTIVES

Why Has Classical Dermatology Become Insufficient?

It is grounded in visual descriptiveness.

1. Classical dermatology diagnoses disease through visible morphological elements—macules, papules, plaques, erosions, and related manifestations. However, this approach reflects consequence rather than cause. Morphological features represent only the surface expression of deeper cellular processes, and their external similarity often conceals fundamentally different pathogenetic origins. Identical symptoms may therefore arise from entirely distinct cellular mechanisms and require different therapeutic strategies.

It is subjective and insufficiently reproducible.
2. Diagnosis largely depends on the clinician’s experience and visual memory. What one specialist identifies as eczema, another may interpret as dermatitis, and a third as mycosis. In the era of digital medicine and precision diagnostics, such a degree of interpretative variability is no longer acceptable.

It fails to explain the dynamics of the skin as a living system.
3. Traditional dermatology captures a static moment of disease but does not account for transitions between states—such as inflammation, regeneration, and remission. Yet it is precisely within these transitions that the true physiology and pathology of the skin are manifested.

It is not integrated with contemporary cellular analytical methods.
4. Modern technologies—such as flow cytometry—permit visualization of tissue not as a surface lesion but as a map of cellular phenotypes and their interactions. Classical dermatology lacks the conceptual and methodological framework required to interpret such data.

It does not meet the demands of personalized medicine.
5. A purely morphological diagnosis cannot explain why different patients with the same clinical form of disease respond differently to therapy. Only phenotypic cellular analysis can reveal these distinctions and thereby advance dermatology toward individualized treatment.

What Has Been Demonstrated?

1. Phenotypic dermatology constitutes a substantiated and reproducible scientific framework grounded in flow cytometry and cytological analysis of the skin. An original method—the skin cytoimmunogram—has been developed and validated, enabling quantitative assessment of cellular subpopulation composition and objective characterization of their phenotypes.
2. It has been demonstrated that the phenotype of a cellular subpopulation—rather than the morphological element of a rash—represents the true measurable unit of skin state.
3. The relationship between alterations in cellular phenotypes and clinical manifestations of skin diseases (including atopic dermatitis, psoriasis, wound processes, and others) has been experimentally confirmed.
4. Biotechnological products developed on the basis of this theory—such as Cellgel—have demonstrated the practical applicability of the phenotypic approach, including accelerated regeneration, activation of CD34⁺ CD45^dim cells, and optimization of tissue repair.

What Changes?

1. Diagnosis ceases to be descriptive and subjective; it becomes measurable and cell-phenotypic.
2. Dermatology transforms from a discipline of observation into a science of analysis and prediction of skin states.
3. The morphological language of disease is replaced by the language of phenotypes, enabling differentiation of conditions with identical external manifestations but distinct cellular origins.
4. Clinical practice acquires tools for patient stratification and objective monitoring of therapeutic effectiveness.
5. For the first time, direct monitoring of dynamic cellular processes in the skin during treatment and recovery becomes possible.

What Comes Next?

1. Creation of an international database of skin-cell phenotypes and a digital “atlas” of skin states as a foundation for standardization of phenotypic analysis.
2. Integration of phenotypic dermatology with single-cell and spatial transcriptomic technologies for spatiotemporal modeling of pathological processes.
3. Application of artificial intelligence for interpretation of cytoimmunograms and prediction of therapeutic response.
4. Development of personalized phenotypic therapies aimed at correcting skin cellular composition based on the individual patient profile.
5. Establishment of next-generation diagnostic and therapeutic platforms integrating laboratory, bioinformatic, and clinical data into a unified system of phenotypic analysis.

Phenotypic dermatology thus marks the end of the descriptive era of cutaneous medicine and inaugurates a new era—an era of measurable, controllable, and predictable skin states.

Foundational Advances

1. Diagnosis becomes quantitative and cell-phenotypic. Clinicians gain the ability to measure skin states at the level of cellular populations rather than relying solely on external manifestations.
2. Treatment becomes personalized. The cytoimmunogram enables therapy selection based on the individual phenotypic profile, prediction of effectiveness, and dynamic treatment adjustment.
3. Prognosis becomes objective. Changes in cellular phenotypes reflect the direction of disease progression—toward remission or exacerbation—making controlled modulation of skin states feasible.
4. Therapeutic monitoring becomes measurable. Instead of subjective assessments of “improvement,” quantitative criteria emerge: balance of inflammatory and regenerative subpopulations and indices of phenotypic activity.
5. Dermatology becomes interdisciplinary. Integration with immunology and cellular biology establishes a new domain—phenotypic medicine of the skin.

Practical Implications

1. Diagnostic Technologies

– Development of standardized panels of phenotypic markers for common dermatologic diseases;
– Implementation of the skin cytoimmunogram in laboratory diagnostics and dermatologic practice.

2. Therapeutic Solutions

– Development of agents aimed at modulation of skin-cell phenotypes (e.g., stimulation of regenerative CD34⁺ cells, suppression of pro-inflammatory Th17/Th22 responses);
– Evaluation of cosmetic and regenerative procedures based on measurable phenotypic shifts.

3. Monitoring and Prevention

– Dynamic monitoring of skin state during therapy and aging;
– Prediction of risks for chronic inflammation and pathological scar formation.

4. Education and Standardization

– Development of training programs in the phenotypic approach for dermatologists, cosmetologists, and researchers;
– Establishment of methodological guidelines for incorporating phenotypic indicators into clinical research.

Research Perspectives

1. Integration with advanced multi-omics technologies, including spatial transcriptomics, proteomics, and metabolomics of the skin.
2. Creation of an international database of skin-cell phenotypes—a digital atlas of normal and pathological states.
3. Development of artificial intelligence algorithms for automated interpretation of skin cytoimmunograms and prediction of disease outcomes.
4. Investigation of regenerative phenotypes and development of agents capable of targeted modulation of cellular profiles.
5. Advancement of the concept of phenotypic medicine, wherein the skin serves as a model organ for studying systemic cellular interactions in the human body as a whole.

AFTERWORD

There was a time when dermatology seemed to me a science of surfaces—a discipline concerned with what is visible to the eye. Yet the more closely I examined the skin of my patients, the more clearly, I understood that what appears to be surface is merely the reflection of an infinitely complex cellular life, of dialogues and conflicts unfolding beyond direct perception. I came to realize that we do not treat spots or plaques; we attempt to influence the behavior of cells, their memory, and their intrinsic drive to restore lost equilibrium. From this realization, the idea of phenotypic dermatology emerged.

It did not arise as a rebellion against tradition, but as an effort to look deeper—toward causes rather than consequences. This path was not solely one of scientific experimentation; it was also a journey marked by doubt, solitude, and the challenge of reexamining established views of the skin. Each experiment, each error, each patent represented a step toward understanding that the skin is a living system of meaning, not merely a covering tissue.

Looking back now, I see that the path of phenotypic dermatology is not the path of a single researcher, but a step taken by science itself toward greater precision and greater humanity. When we begin to understand the cell not as an object, but as a participant in the life of the organism, we bring medicine closer to the person.

I believe this work is only a beginning. The era of descriptive medicine is giving way to an era of awareness—an era in which behind every phenotype there is hope, and behind every cell, an individual life.

Author: Sergey V. Goltsov, MD, PhD