Palm Blisters, Sole Blisters? Dyshidrosis?!
Table of Contents
One of the skin conditions frequently seen in Korean medicine clinics is dyshidrosis. Dyshidrosis refers to an inflammatory skin condition primarily appearing on the hands and feet, accompanied by vesicles or blisters.
Personal Reflections on Dyshidrosis
Personally, I've thought about dyshidrosis quite a lot and researched extensively. Questions like "Why do vesicles and blisters appear?", "Why specifically on the hands and feet?", "Is it idiopathic (unknown cause) or an allergy?", "Is it related to hyperhidrosis or not?", "Does it coexist with other types of eczema?" often lead to a chain of further questions.
Similar to an 'id reaction,' secondary toxic reactions due to primary infections like fungal or bacterial infections can appear on the hands and feet, and it has been pointed out that some patients who come in thinking they have dyshidrosis may need to consider this possibility.
Histological findings, presented as evidence that heavy metal allergic reactions (such as to nickel) become inflamed around sweat glands along with sweat secretion on the hands and feet (where eccrine sweat glands are abundant), could also offer a partial explanation for why it appears on the hands and feet.
Ambiguity of Dyshidrosis
I also wonder if it's difficult to encompass all manifestations under the single name "dyshidrosis." Cases presenting as allergic reactions to specific allergens are often filtered out by dermatologists, making them rare among patients seen in Korean medicine clinics.
Blistering Disorders
I found an excellent lecture material on blistering disorders. Those interested can refer to here.
A "blister" is called `muljip` or `supo` in Korean. It refers to a form where fluid accumulates within or below the epidermal layer. It is said to be distinguished by size, with a threshold of 0.5cm, into `vesicles` and `bullae`.
Causes and Differential Diagnosis Points
The causes are very diverse. When a blistering lesion appears, information such as the patient's age, the area where it first started, involvement of mucous membranes, and the main lesion site can be useful for differential diagnosis. It is important to accurately gather necessary information during the history-taking process.
Classification Based on Blister Depth
The table above (implied) categorizes based on the location where fluid accumulates. As mentioned, blistering disorders are essentially conditions where fluid accumulates in the epidermis, and if we further divide the areas of fluid accumulation within the epidermis in detail, they are broadly spoken of as three types of locations.
- Subcorneal: Cases where fluid accumulates directly beneath the stratum corneum.
- Intra-epidermal: Cases where fluid primarily accumulates within the epidermal layer.
- Dermo-epidermal: A form where the epidermal-dermal junction separates and fluid accumulates.
Classification Based on Histological Differences
Blister types can be classified according to histological differences. To explain Spongiosis and Acantholysis:
- Spongiosis: A condition where cells separate from each other, and fluid accumulates in the intercellular space, causing swelling.
- Acantholysis: A state where desmosomes, the intercellular adhesion structures connecting keratinocytes in the epidermis, are broken.
Diseases Related to Dyshidrosis
Dyshidrosis is also known as pompholyx eczema. It is said to be one of the representative types of spongiotic dermatitis. You can observe blisters located relatively deep within the epidermal layer.
To summarize:
- When blisters or vesicles appear, what needs to be observed includes the lesion site, involvement of mucous membranes, as well as their shape, size, and depth.
- Careful observation of differences in shape and depth can provide diagnostic clues.
- Generally, blisters in hand and foot eczema or dyshidrosis tend to be deep-seated spongiotic vesicles; therefore, if their appearance differs, it may be necessary to consider other causes.