The Shift To Morphological Classification Of Skin Diseases

Monderma

Oliver Belcher

11 Jun 2025

Dermatology moved from humoral belief
Plenck shaped early morphology
Willan refined lesion categories
Morphology supports diagnosis today
Modern care guided by Monderma

Dermatology has evolved through shifts in understanding, and many readers recognise how daily skin changes often reflect broader diagnostic patterns used in clinical care.

In this article we outline how humoral ideas shaped early dermatology, how morphology replaced these beliefs after 1800, and why these developments continue to inform diagnosis.

Ancient Practice & Humoral Views

Humoral thinking linked eruptions to shifts in blood, phlegm, yellow bile, and black bile. Care aimed to correct fluid balance rather than observe detailed skin features.

Early Developments Before 1800

Year	Event
c.1550 BC	Ebers Papyrus describes empirical care [1].
c.460 BC	Hippocrates links eruptions to humours.
129 AD	Galen standardises humoral diagnostics.
1025	Avicenna integrates humoral concepts [1].
1572	Mercuriali publishes first skin text.
1714	Turner blends notes with humoral ideas.
1777	Lorry describes skin as an organ.

Table 1: Pre 1800 developments

Plenck & Willan As Key Figures

Plenck classified 115 conditions by features such as spots, crusts, pustules, vesicles, and scales [1]. This terminology supported clearer communication across practice.

Willan refined this structure into papules, scales, rashes, bullae, pustules, vesicles, tubercles, and macules with illustrated detail [7]. His work shaped modern descriptions used for eczema, psoriasis, and infections.

Post 1800 Scientific Growth

Year	Event
1801	Saint Louis Hospital established for dermatology.
1808	Willan completes On Cutaneous Diseases [7].
1813	Bateman broadens access to morphology.
1836	First US skin clinic documented [1].
1856	Hebra integrates pathology [1].
1894	Unna advances histopathology [1].
1903	Finsen develops phototherapy [1].
1963	Lasers enter dermatology [1].
1970s	Fitzpatrick scale introduced.
2020s	AI supports lesion analysis [4].

Table 2: Post 1800 progress

Morphology In Clinical Diagnosis

Morphology guides recognition of conditions such as epidermolysis bullosa, where fragile skin forms fluid filled blisters [8]. It also helps describe macules, papules, and raised tubercles [1].

Cancer assessment relies on lesion form. Basal cell carcinoma grows slowly in the epidermis [3], while squamous cell carcinoma forms firm pink lumps originating from keratinocyte cells [2]. Microscopy confirms these findings.

Psoriasis arises when immune activity accelerates cell turnover, and morphology supports early recognition and care [5]. These visual features remain central across practice.

Humoral Vs Morphological Understanding

Humoral practice viewed acne as excess heat or fluid, while morphology describes lesions by form. This clarity supports care across common UK concerns, including acne and psoriasis, which affects 1.3 to 2.2% of adults [5,6].

AI tools now assess lesions to support early triage [4]. These advances show how morphology continues to guide diagnostic confidence and clinical outcomes.

Conclusion

The work of Plenck and Willan shifted dermatology from humoral theories to careful observation, laying the foundation for modern terminology, diagnosis, and evidence based treatments. Their contributions continue to inform how skin conditions are understood and managed today.

If you would like personalised skincare informed by modern dermatological principles, you can explore a tailored formula through Monderma.

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