Focal hand dystonia (FHD) is characterized by dystonic hand contractions that are often aggravated by purposeful actions and may be specific to a particular task. The term “occupational dystonia” is used when dystonia affecting performance of the job arises in individuals with a particular occupation, usually an occupation requiring repetitive and excessive fine motor activity.

One task-specific FHD, writer’s cramp, causes disabling spasms of the hands when attempting to write, and is particularly likely in people whose profession involves excessive writing. Musician’s dystonia (cramp) is applied to a focal dystonia localized to hand muscles controlling fine movements of the digits or the embouchure muscles involved in playing instruments.

Injection of botulinum neurotoxin (BoNT) is effective in writer’s cramp and other occupational dystonias. This chapter discusses the different common patterns of dystonic movement of the hand and arm, identifies the particular muscles active in each dystonia pattern to aid in target selectio, and illustrates the muscular anatomy and injection approach using anatomical diagrams. Guidance of injections with EMG is discussed. Dosing recommendations for three different BoNT formulations are tabulated.

Cervical dystonia (CD) is an idiopathic focal dystonia characterized by abnormal head and neck posture caused by tonic involuntary contractions in a set of cervical muscles. Four subtypes, based on the principal direction of posture, consist of:

• - Torticollis: Rotation of the head left or right in the transverse plane.

• - Lateralcollis: Head tilt toward left or right shoulder, in the coronal plane.

• - Anterocollis: Head tilt forward, with neck flexion in the sagittal plane.

• - Retrocollis: Head tilt backward, with neck extension, in the sagittal plane.

The clinical spectrum of CD is extremely variable: the 54 muscles involved in head and neck posture may show complex mixtures of involvement, unilateral or bilateral, with contractions of tonic, tremulous or myoclonic character. Currently, the most effective, and now first-line treatment of CD, has become intramuscular injection of botulinum toxin.

This chapter enumerates the different muscles involved in major subtypes of CD, grouped by anatomical location, and their principal direction of action. Sets of muscles involved in different head postures are presented in tabular format for easy selection and targeting. Dose ranges for individual muscles are tabulated for each of the four commonly used botulinum neurotoxin preparations.

Piriformis syndrome is entrapment of the sciatic nerve by the piriformis muscle, causing sciatica. One estimate puts the incidence of sciatica of non-disc origin as equal to or greater than that of herniated disc. Symptoms of piriformis syndrome include buttock pain and tenderness and sciatica, with pain radiating distally. This chapter reviews the three main pathogenetic factors in the development of piriformis syndrome: anatomical variations, nerve compression and nerve adhesion. The approach to patient examination, and diagnosis using electrophysiogical methods (H-reflex), the FAIR test, electromyography and neural scanning using MRI are discussed.

Injections of botulinum neurotoxin (BoNT) are a successful and largely innocuous treatment for piriformis syndrome. The application of BoN) types A and B is detailed, and injection techniques are illustrated with anatomical diagrams and dosing recommendations. The importance of injection guidance techniques, focusing on electromyography, is stressed.

Botulimum neurotoxin food poisoning (botulism) has probably afflicted humankind as long as humans have preseved and stored food. In tenth-century Byzantium, blood sausage manufacture may have been banned for this reason. Botulinum preparations were suggested to Indian maharajas as a means of assassinating enemies. Botulism outbreaks in Germany in the eighteenth and nineteenth centuries led to warnings against harmful consumption of blood sausages.

In 1820, Justinus Kerner published case histories detailing the signs and symptoms of the disease we now call botulism, and postulated a biological causative agent that developed under anaerobic condition and affected the motor and autonomic nervous systems. The bacillus Clostridium botulinum was identified by van Ermengem in 1895. multiple serological subtypes were isolated in the early twentieth century, followed by identification of wound botulism in 1950, and infant botulism in 1976. Use as a bioweapon was considered in World War I. Botulinum neurotoxin type A was isolated in the 1920s. The US government investigated its deployment in World War II. After the war, clinically therapeutic formulations were prepared in the USA and Britain.

Patients with vulval problems have often spent many years in fruitless pursuit of a diagnosis and effective treatment. The reasons for this are varied.

White- or pale-appearing patches on the vulva are uncommon. Most white vulval lesions are lichen sclerosus. However, vulval intra-epithelial neoplasia (VIN) may also appear white, and dermatitis complicated by lichenification or lichen simplex chronicus may also appear white.

In the past, white patches on the vulva were called ‘leukoplakia’. This term rarely appears anymore and should be regarded as out of date. It should be abandoned in favour of specific diagnostic terms. Because of the potential diagnostic confusion, white lesions on the vulva in adults should be biopsied if possible.

The most common presentation of a vulval skin problem is an itchy red rash. This group includes inflammatory dermatoses, infections, hypersensitivity reactions and one malignancy.

Dermatitis, psoriasis and chronic vulvo-vaginal candidiasis are all very common causes of red, itchy rashes with variable degree of scaling. Corticosteroid-induced dermatitis occurs when moderate to potent topical corticosteroid is used for long periods of time. Tinea is uncommon and extra-mammary Paget’s disease and oestrogen-hypersensitivity vulvitis are rare.

On first sight, all of these conditions look much the same. A combination of history taking, investigation and response to therapy will ultimately enable a diagnosis and effective treatment.

Topical steroids on the vulva are very safe if used properly and supervised regularly. We provide a guide to the safe and effective use of these essential drugs.

Topical corticosteroids (TCSs) are a dermatological therapeutic mainstay. They are appropriate in the treatment of most inflammatory dermatoses everywhere on the skin. This includes the vulva.

Used in different ways in different situations, and if used appropriately and correctly, TCSs are very safe. For instance, in lichen sclerosus and lichen planus, they are used continuously, but in psoriasis and dermatitis, they are used intermittently, first for initial treatment and then for flare ups. Details of how to treat these conditions are found in the appropriate chapters.

Diseases of the vulva that are primarily erosive or ulcerative are uncommon. Notwithstanding, fissures or excoriations can occasionally complicate almost any dermatological disease of the vulva.

Common conditions such as dermatitis and psoriasis may become eroded by scratching, and allergic contact dermatitis often causes such severe oedema that blistering occurs.

Certain conditions, which are not usually ulcerative or bullous, may have rare variants that are, for example, the bullous variant of lichen sclerosus. Vulval cancer may ulcerate when advanced.

This chapter focuses on conditions where ulceration or erosion are a characteristic part of the disease. It is important to understand the difference between ulceration and erosion: ulceration means full-thickness loss of the epithelium, whereas erosion means partial-thickness epithelial loss.

When a pre-pubertal girl presents with an itchy or sore vulval rash, she is usually assumed to have thrush or a urinary tract infection. Poor hygiene or sexual abuse may also be considered. In fact, none of these are likely to be true.

For a patient to experience symptoms from candidiasis, the vagina must be oestrogenised. It therefore does not occur in pre-pubertal girls. Urinary tract infections do not result in rashes unless prolonged incontinence is present (although contact of urine with inflamed skin may cause stinging), sexually abused children rarely have physical signs and over-zealous hygiene is more likely to produce a rash than lack of hygiene.

Vulval disease in children is less common than in adults. In both adults and children, dermatitis, psoriasis and lichen sclerosus (LS) are the most common dermatoses that cause a chronic vulval rash. Infective vaginitis is rare in children.

Vulvodynia is a term that every doctor with an interest in vulval disease has heard of and read about. You will notice, however, that it is not the name of this chapter. This is because vulvodynia is by definition a collection of symptoms, not a disease entity in itself.

Vulvodynia is in fact a poorly defined concept that simply means vulval pain. When your patient presents with vulval pain, you need to sort her into a meaningful diagnostic group. The management of each sub-type is different. There is no single therapy that can be applied to all patients yet the existing literature on the subject can give the impression that there is.

Vulvodynia is a term developed by the International Society for the Study of Vulvar Disease (ISSVD) in 1983. Their current definition is ‘vulvar discomfort, most often described as burning pain, occurring in the absence of relevant visible findings or a specific, clinically identifiable neurologic disorder’.

The vulva is part of the skin, therefore, many common lesions found on the skin are also found on the vulva. Some of these lesions can be found anywhere; others are very specific to female genital skin.

This is also true of malignancy: most malignant lesions of the vulva are skin cancers. However, when skin cancer occurs on the vulva, it may have a more serious prognosis than equivalent lesions found on the rest of the skin. Extra-mammary Paget’s disease is a specific vulval condition.

This chapter discusses persistent vaginitis that is not infective in aetiology. This is not only distressing for patients, but diagnostically challenging because the available tests are often unhelpful.

In chronic vulvitis, chronic thrush represents the minority (about 20%) of all cases. Many patients tell us that their doctor prescribed anti-fungal medication without either examining them or taking a vaginal swab.

Multiple courses of anti-fungals should not be given without confirmation of candidiasis on vaginal culture. Particularly for patients with chronic vulvovaginal candidiasis, the length of time that the patient needs to be withdrawn from such agents before vaginal culture is positive again can be many weeks. We therefore strongly recommend that patients always have a vaginal swab before any treatment is commenced.

The complication is that in many cases of genuine candidiasis, swabs are negative, mostly due to anti-fungal use. In this scenario, history taking is key.