Key words
pain - lower limbs - skin
Introduction
Pain in the lower limbs is a common symptom. Suspecting a venous or at least a vascular
origin of the pain, many patients seek an opinion from specialist in vascular diseases.
Contrary to their expectations, a neuroskeletal cause in the lower back is often responsible
[1]. Astonishingly, however, dermatological conditions are much less in focus than varicose
veins when painful legs are the problem.
Methods
Starting with the symptom of non-vascular leg pain, this article presents skin diseases
of varying aetiology. It focuses on dermatological diseases that more commonly affect
the legs and describes the clinical picture of conditions frequently seen in dermatology
or phlebology outpatient clinics.
Results
A wide variety of dermatological conditions may affect the lower limbs and be associated
with pain. Pain may occur in numerous skin diseases ([
Table 1
]), so the following addresses specific examples of typical clinical conditions.
Tab. 1
Aetiology and symptoms of leg pain
|
Main group
|
|
|
Allergic conditions
|
Urticaria, acute or chronic recurrent
Drug rashes
Toxic epidermal necrolysis
Allergic vasculitis
Allergic contact dermatitis
|
|
Dermatitis
|
Toxic or allergic contact dermatitis
Solar dermatitis
Atopic dermatitis (eczema)
|
|
Autoimmune diseases
|
Leukocytoclastic vasculitis
Psoriasis
Scleroderma
Bullous pemphigoid
Pemphigus vulgaris
Acquired epidermolysis bullosa
Pyoderma gangrenosum
|
|
Infections
|
Erysipelas
Phlegmon
Herpes zoster
Herpes simplex
Impetigo
Wound infections
|
|
Livedo conditions
|
Livedo vasculopathy
Livedo vasculitis
Sneddon’s syndrome with livedo racemosa
|
|
Pruriginous conditions
|
Prurigo nodularis
Prurigo simplex
|
|
Tumours
|
Cutaneous metastases
Cutaneous lymphoma
Ulcerating malignant melanoma
Ulcerating non-melanocytic skin cancer
Neurinoma
Lipoma/angiolipoma
|
|
Genodermatoses
|
Epidermolysis bullosa dystrophica
|
Individual conditions
Soft tissue infections of the skin
Erysipelas
Erysipelas is a common infection of the skin. As a rule, the infection is due to β-haemolytic
streptococci belonging to group A, more rarely to groups B, C, D or staphylococci.
The organisms enter through small injuries (entry portals), penetrate the dermis,
and spread through the lymphatic channels. The onset is typically acute with fever
and shivering, while the characteristic sharply demarcated and very painful redness
follows later. Erysipelas very commonly affects the legs, as the entry portal is often
an area of tinea pedis (see [
Fig. 1
]). Erysipelas requires systemic antibiotic therapy for at least 7–10 days [2]. Blister formation, bleeding, and necrosis may occur as complications. In rare cases,
erysipelas may lead to sepsis.
Fig. 1 Erysipelas on the right lower leg. Entry portal is an interdigital fungal infection
between the toes.
Inadequate treatment of erysipelas or neglecting to treat the entry portal makes recurrence
more likely. Recurrent erysipelas may lead to irreversible damage of the lymph channels
and secondary lymphoedema may ensue [3]. This, in turn, may be the cause of further recurrences (see [
Fig. 2
]). Further risk factors for recurrent erysipelas are anatomical considerations such
as a pretibial site [4], concomitant venous insufficiency and/or lymphoedema [5], [6], and previous surgical procedures [7]. Furthermore, in such cases of chronic recurrent erysipelas, chronic pain in the
affected limb is a very common symptom. Given the potential development of secondary
lymphoedema, appropriate compression therapy should be included in the therapeutic
approach to erysipelas.
Fig. 2 Recurrent erysipelas on the left lower leg.
Phlegmon
It is not easy to distinguish between erysipelas and a phlegmon. The course of a phlegmon
involves deeper structures with purulent liquefaction and may result in extensive
areas of necrosis or even sepsis (see [
Fig. 3
]). There is often a mixed streptococcal and staphylococcal infection. The clinical
picture is to be taken seriously, as involvement of the fascia (necrotising fasciitis)
may have a fulminating course [8]. Besides the necessary surgical intervention, systemic antibiotic therapy is the
mainstay of treatment.
Fig. 3 Phlegmon of the left foot and lower leg that required debridement.
Herpes zoster
Triggered by the reactivation of varicella-zoster virus in the posterior spinal ganglion,
initial paraesthesias, such as burning or pain, occur before the typical distribution
of blisters appears in the corresponding dermatome (see [
Fig. 4
] and [
Fig. 5
]). Relevant dermatomes in the leg are L3 to S1. Underlying malignant disease or immune
deficiency should be ruled out in cases where several dermatomes are affected. Herpes
zoster infection is characterised by intense pain that requires adequate systemic
analgesia. The WHO analgesic ladder is to be recommended [9], [10].
Fig. 4 Herpes zoster infection of the left leg, beneath the picture of vasculitis.
Fig. 5 The same patient as in figure 4, posterior view. It can be seen how the blisters
are arranged within the dermatome.
Dermatitis
The term dermatitis is generally used to describe inflammatory diseases of the skin
of varying aetiology. Extensive acute inflammation in particular may be intensely
painful. Solar dermatitis (see [
Fig. 6
]), toxic dermatitis (e. g. phytophotodermatitis), and allergic contact dermatitis
(see [
Fig. 7
]) can be mentioned in relation to painful cutaneous processes in the legs. The identification
and future avoidance of the trigger are of key importance for these examples. Topical
steroids are used in the first line of treatment.
Fig. 6 Solar dermatitis of the lower leg. The patient fell asleep on the beach.
Fig. 7 Allergic contact dermatitis of the lower leg and forefoot after using a lanolin-containing
ointment.
Inflammation and pain as symptoms
Erythroderma
Erythroderma is understood to mean intense and usually widespread reddening of the
skin due to inflammatory skin disease. It is a very severe form of disease and may
be associated with pain, especially in the lower legs. The trigger may be acutely
exacerbated psoriasis vulgaris [11], [12] or cutaneous lymphoma [13]. Erythroderma always needs a thorough diagnostic work-up, including dermatohistological
and immunohistological examinations. Since erythroderma is not considered to be a
clinical condition in its own right but rather a symptom or expression of a severe
underlying disease, the various individual targeted treatments will not be considered
in detail at this junction.
Urticaria
The characteristic symptom of acute and chronic urticaria is the presence of extremely
itchy wheals that occur after the degranulation of mast cells lying in the subepidermal
layers. Histamine and other inflammatory mediators are released. In some cases, headaches
and joint pains or gastrointestinal symptoms occur together with the wheals. This
can be explained by the activation and degranulation of extracutaneous mast cell populations
[14]. The acute forms of urticaria are treated with antihistamines and, in some cases,
with systemic steroids. Chronic urticaria requires a thorough diagnostic work-up in
a specialist facility – basically the chronic spontaneous form has to be distinguished
from the chronic inducible form. The treatment of chronic urticaria follows a stepwise
approach, in which second generation H1-antihistaminienes are first increased up to
four times the dose, omalizumab is then added if the initial treatment is not effective,
and lastly ciclosporin is prescribed [15].
Prurigo/chronic pruritus
In many cases intense itching is experienced as pain, for example, the patient cannot
distinguish whether it currently itches or hurts. The reason for this may be that
the neurophysiology of itching and of pain have a lot in common [16], [17]. A typical skin condition that is characterised by itching and pain is nodular prurigo
(prurigo nodularis). Nodular prurigo may also occur as a prodromal symptom of myeloproliferative
diseases. It has been described in association with Hodgkin’s disease [18]. Prurigo usually responds very well to topical steroids.
Leg pain may occur in association with dermatological conditions. It is of significance
in infections of the skin, as it may occur even before the appearance of the typical
inflammatory lesions. In particular, it is a prodromal symptom of herpes zoster infection.
Leg pain may be present in non-infectious dermatological conditions as a symptom of
an underlying inflammatory or autoimmune disease.
