Fungal Infection of Nails

Fungal infection of the nails has been classified into four types :

1. White superficial onychomycosis presents with diffuse or speckled white discoloration of the surface of the toenails. It is caused primarily by Trichophyton mentagrophytes, which invades the nail plate. The organism may be scraped off the nail plate with a blade, but treatment is best accomplished by the addition of a topical azole antifungal agent.

2. Distal subungual onychomycosis presents with foci of onycholysis under the distal nail plate or along the lateral nail groove, followed by development of hyperkeratosis and yellow-brown discoloration. The process extends proximally, resulting in nail plate thicken and separation from the nail bed. Trichophyton rubrum and, occasionally, T. mentagrophytes infect the toenails; fingernail disease is almost exclusively due to T. rubrum, which may be associated with superficial scaling of the plantar surface of the feet and often of one hand. These dermatophytes are found most readily at the most proximal area of the nail bed or adjacent ventral portion of the nail plates that are involved. Topical therapies such as ciclopirox 8% lacquer may be effective for solitary nail infection. Because of their long half-life in the nail, terbinafine or itraconazole may be effective when given as pulse therapy (1 wk of each mo for 3–4 mo). Either agent is superior to griseofulvin, fluconazole, orketoconazole. The risks, the most concerning of which is hepatic toxicity, and costs of oral therapy must be weighed carefully against the benefits of treatment for a condition that generally causes only cosmetic problems.

Onychomycosis and Diabetes: Patient Case Challenges

Onychomycosis is a common infection that can lead to potentially severe complications in patients who have impaired circulation, peripheral neuropathy, or are immunocompromised. This infection is particularly common in patients with diabetes, many of whom have one or more of these conditions. Onychomycosis treatment reduces risks, but is complicated by the potential for drug-drug interactions between systemic antifungals and the large number of medications often taken by these patients. Several topical therapies are available, including two newer agents that became available in 2014, increasing the potential for individualized treatment selection.

The following case-based activity will test your ability to select appropriate therapies in patients with type 2 diabetes and onychomycosis, while bringing you up to date on risks and management of toenail infections in this vulnerable patient population.

Case :

Albert is a 55-year-old man with type 2 diabetes who presents to your office with thickened, elongated, yellowed toenails (picture shown below). He reports that he first noticed the changes in his toenails about 3 months ago, at which time most of his nails were already involved. Albert was diagnosed with type 2 diabetes 4 years ago, and his blood sugar is currently poorly controlled on metformin alone. He has elevated triglyceride levels for which he is taking a low dose of simvastatin. He is clinically obese, which may have contributed to the fact that he did not notice his toenail infection until it was well entrenched.

On clinical examination, you observe that all of Albert’s toenails are yellow in color and 6 have white lateral streaks. Two nails show involvement extending proximally to the lunula. Several nails, including both great toenails, show subungual hyperkeratosis that is greater than 2 mm thick and two are onycholytic. You estimate that at least 75% of the overall area of Albert’s toenails is infected, with involvement seen in all 10 toenails.

Which of the following clinical characteristics is a risk factor for onychomycosis in patients with diabetes?
A. Female sex
B. Neuropathy
C. Renal dysfunction
D. Younger age

Answer: B. Neuropathy

Discussion: Patients with diabetes can develop peripheral neuropathy, which contributes to the risk of developing onychomycosis, perhaps because this condition impedes proper foot care and allows unrecognized trauma to the nail. 

Men with diabetes are approximately 3 times more likely to develop onychomycosis compared with women with diabetes, and the prevalence of onychomycosis increases with age. Onychomycosis does not seem to be linked to the presence or absence of renal dysfunction in patients with diabetes.

Onychomycosis and Diabetes
Onychomycosis is highly prevalent in patients with diabetes. A North American study of 550 consecutive patients with diabetes found abnormal-appearing toenails in 46% of patients and mycological evidence of onychomycosis in 26% of patients. After adjusting for age, the researchers calculated a 34.9% prevalence in the overall US diabetes population, an estimate that is similar in other studies. Onychomycosis was 2.77 times more likely in patients with diabetes compared with individuals without diabetes. Prevalence in the one-third of patients with type 1 diabetes in this study was lower but still elevated compared with individuals without diabetes, with an odds ratio of 1.69. Onychomycosis was also 3 times more likely in men compared with women with diabetes.

A 26 year old man with lesions on his body...

A 26-year-old man is seen for an upper respiratory infection. After removing his shirt, you notice the lesions shown in the picture below. He reports that his father has similar lesions.

The differential diagnosis should include
A) Hypothyroidism
B) Addison’s disease
C) Multiple sclerosis
D) Neurofibromatosis
E) Gardner’s syndrome

Answer:

An 18-year-old woman presents to your office complaining of tender nodules that have developed on the lower extremities.

An 18-year-old woman presents to your office complaining of tender nodules that have developed on the lower extremities.

She has no other symptoms. She continues with her oral contraceptives but has not started any new medications. She denies any fevers and has no history of recent trauma.

The likely diagnosis is
A) Erythema multiforme
B) Erythema nodosum
C) Lyme disease
D) Pyoderma gangrenosum
E) Rheumatoid arthritis

Answer:

Erythema ab igne

Erythema ab igne (EAI, also known toasted skin syndrome) is a skin condition caused by over exposure to infrared radiations. 

Initially, the skin in erythema ab igne patients is often mildly erythematous; however, after repeated heat exposures, the classic blue, purple, or brown reticulated hyperpigmentation develops.

A history of prolonged or repeated skin exposure to mild-to-moderate heat or infrared radiation that is below the threshold of thermal burn (less than 45°C) should raise suspicion. The duration of exposure varies from weeks to years. 

Examples include: 

• local application of hot water bottles or heating pads used for pain relief, 
• Direct exposure to the optic drive, battery, or ventilation fan of computers. Resting a laptop computer on the thigh (laptop computer-induced erythema ab igne).
• Repeated exposure to heated car seats, space heaters, or fireplaces. 
• Repeated or prolonged exposure to a heater is a common cause of this condition in elderly individuals.
• Occupational hazards of silversmiths and jewellers (face exposed to heat), bakers and chefs (arms)

                        Erythema ab igne as seen on the thigh after prolonged resting of laptop 

Clinical features: 

Erythema ab igne (EAI) is generally localized and usually well-demarcated, presenting with a reticulated macular pattern of erythema and hyperpigmentation . Cutaneous lesions are commonly asymptomatic, although patients may complain of pruritus or a slight burning sensation.

Tinea versicolor - Clinical Presentation And Treatment

Tinea versicolor is a common skin infection caused by the organism Pityrosporum orbiculare (also known as Malassezia furfur, Pityrosporum ovale, or Malassezia ovalis). The condition usually affects adolescents and young adults in tropical environments. The organism is a yeast that is a constituent of the normal skin flora.

Predisposing factors: A number of factors may trigger conversion to the mycelial or hyphal form that is associated with clinical disease, including

• hot and humid weather, 
• use of topical oils, 
• hyperhidrosis, and 
• immunosuppression. 

Clinical features: Tinea versicolor usually responds to medical therapy, but recurrence is common, and long-term preventative treatment may be necessary. Versicolor refers to the variety and changing shades of colors present in this condition. Lesions can be hypopigmented, light brown, or salmon-colored macules. A fine scale is often noted, especially after scraping. Individual lesions are typically small, but frequently coalesce to form larger lesions. Typically the lesions are limited to the outer skin, most commonly on the upper trunk and extremities, and are less common on the face and intertriginous areas. Most patients are asymptomatic; however, some may complain of mild pruritus.

Neonatal Dermatoses - Different Types Explained with Pictures For Better Understanding.

Skin disorders are one of the most common problems in pediatrics. Never underestimate parental concerns about their child’s skin. Unlike many disease processes, the skin is visible and noticeable to parents and others. Examination of the skin requires observation and palpation of the entire skin surface under good light. Do not forget to look at the eyes and mouth for mucous membrane involvement. Examination should include onset, duration, and inspection of a primary lesion. It is also important to note secondary changes, morphology, and distribution of the lesions.

Neonatal Dermatoses

1. Cutis Marmorata

• Transient, blanchable, reticulated mottling occurs on the skin exposed to a cool environment.
• No treatment is necessary; the condition generally resolves by 1 year of age.
• If it persists, consider hypothyroidism, heart disease, or other associated abnormalities.

2. Erythema Toxicum Neonatorum

• Scattered erythematous papules and pustules may occur anywhere on the body .
• This self-limited condition generally appears in the first week of life and resolves within 1 month.

Drug Induced Lupus Erythematosus

Drug-induced lupus erythematosus is a disorder that is brought on by a reaction to a medicine. In drug induced lupus not all the typical features of systemic lupus erythematosus are seen, with renal and nervous system involvement being unusual. It usually resolves on stopping the drug.

The most common medicines known to cause drug-induced lupus erythematosus are:

• Isoniazid
• Hydralazine
• Procainamide

Other less common drugs may also cause the condition. These may include:

• Anti-seizure medications
• Capoten
• Chlorpromazine
• Tumor-necrosis factor (TNF) alpha inhibitors (such as etanercept, infliximab and adalimumab)
• Methyldopa
• Minocycline
• Penicillamine
• Quinidine
• Sulfasalazine

Symptoms tend to occur after taking the drug for at least 3 to 6 months.

Discoid lupus erythematosus - A Brief Discussion

Discoid lupus erythematosus is a benign disorder generally seen in younger females. It very rarely progresses to systemic lupus erythematosus (in less than 5% of cases).

Discoid lupus erythematosus is characterized by follicular keratin plugs and is thought to be autoimmune in etiology.

Clinical Features

• erythematous, raised rash, sometimes scaly
• may be photosensitive
• more common on face, neck, ears and scalp
• lesions heal with atrophy, scarring (may cause scarring alopecia), and
• pigmentation

Management

A 12-year-old boy presents with a crusted honey-brown lesion that affects his face

A 12-year-old boy presents with a crusted honey-brown lesion that affects his face. The rash began as red macules 3 days earlier. The best treatment is

A) Intramuscular ceftriaxone
B) Topical hydrocortisone cream
C) Oral ciprofloxacin
D) Topical mupirocin ointment
E) Oral acyclovir

Answer:

Discoid Eczema (Nummular Dermatitis)

Eczema or Dermatitis is a term used to describe conditions in where there is inflammation of skin. There are several types of eczema and Discoid eczema is one type which causes round or oval red patches of inflamed skin. It is also known as Nummular dermatititis which means coin shaped lesions. 

Discoid eczema is usually seen in adults with dry skin although it can affect teenagers and young children, but this is rare.

Clinical Features

• typically present as round or oval plaques on the extremities
• the lesions are extremely itchy
• central clearing may occur giving a similar appearance to tinea corporis

Some other symptoms might include:

A 29-year-old man presents to his doctor with a rash ...

A 29-year-old man presents to his doctor with a rash (shown in picture below). The rash does not itch and has been present over the last week. A large, red area developed first, followed by a more generalized rash that is now present.
Physical examination shows that the rash appears in a Christmas-tree pattern on his chest and back.

The most likely diagnosis is
A) Pityriasis rosea
B) Tinea versicolor
C) Herpes zoster
D) Varicella
E) Lyme disease

The answer is

Dermatofibroma

Dermatofibromas (also known as histiocytomas) are common benign fibrous skin lesions. They are caused by the abnormal growth of dermal dendritic histiocyte cells often following a precipitating injury. Common areas include the arms and legs and occurs more often in women.

Etiology: Traditionally, dermatofibromas were attributed to a reaction to trauma such as insect bites. However, the precise aetiology is unclear. Some believe them to be benign neoplasms rather than reactive in origin.

Pathology: The most common dermatofibromas contain a mixture of fibroblasts, macrophages and blood vessels. Most involve the dermis and may extend to the subcutis. A number of less common variants where the histology differs ,such as the aneurysmal fibrous histiocytoma, hemosiderotic fibrous histiocytoma, cellular fibrous histiocytoma and epithelioid fibrous histiocytoma, have been described. Different types are associated with different behaviours and outcomes.

Clinical Signs and Symptoms: Dermatofibromas are most often found on the arms and legs of women. They are small brown or reddish-brown mobile nodules, and they feel quite firm. They may be tender to touch. Many lesions demonstrate a "dimple sign," where the central portion puckers as the lesion is compressed on the sides. They generally do not change in size.

A Skin lesion that developed Over A 4 week period....

The pictured skin lesion developed over a 4-week period. The most likely diagnosis is
A) Melanoma
B) Basal cell carcinoma
C) Keratoacanthoma
D) Dermatofibroma
E) Molluscum contagiosum

Answer:

Introduction to Folliculitis, furuncles, and carbuncles

Folliculitis: A bacterial infection of the hair follicle, folliculitis causes the formation of a pustule of the hair follicle opening. The infection can be superficial (follicular impetigo or Bockhart’s impetigo) or deep (sycosis barbae).

Furuncles, commonly known as boils, are another form of deep folliculitis. 

Carbuncles are a group of interconnected furuncles. 

The prognosis depends on the severity of the infection and the patient’s physical condition and ability to resist infection.

Causes
The most common cause of folliculitis, furuncles, or carbuncles is coagulasepositive Staphylococcus aureus. 

Predisposing factors include 

• an infected wound, 
• moisture, 
• obesity, 
• diabetes mellitus, 
• skin disease, 
• poor hygiene, 
• debilitation, 
• tight clothes, 
• friction, and 
• immunosuppressive therapy.

Signs and symptoms
Folliculitis, furuncles, and carbuncles have different signs and symptoms.

Introduction to Kaposi’s sarcoma

Kaposi’s sarcoma, a cancer of the lymphatic cell wall, affects tissues under the skin or mucous membranes that line the mouth, nose, and anus. In recent years, the incidence of Kaposi’s sarcoma has risen dramatically along with the incidence of human immunodeficiency virus (HIV) infection. It’s now the most common HIV-related cancer.
Kaposi’s sarcoma causes structural and functional damage. It progresses aggressively, involving the lymph nodes, the viscera and, possibly, GI structures.

Etiology
The exact cause of Kaposi’s sarcoma is unknown, but the disease may be related to immunosuppression. Genetic or hereditary predisposition is also suspected.

Signs and symptoms

The initial sign of Kaposi’s sarcoma is one or more obvious lesions in various shapes, sizes, and colors (ranging from red-brown to dark purple) that appear most commonly on the skin, buccal mucosa, hard and soft palates, lips, gums, tongue, tonsils, conjunctivae, and sclerae.
With advanced disease, the lesions may join, becoming one large plaque. Untreated lesions may appear as large, ulcerative masses.

                           Kaposi's Sarcoma Seen as a tumor on the roof of the mouth

                                                    Kaposi Sarcoma Affecting the skin
Other signs and symptoms include:

• a history of HIV infection
• pain (if the sarcoma advances beyond the early stages or if a lesion breaks down or impinges on nerves or organs)
• edema from lymphatic obstruction
• dyspnea (in cases of pulmonary involvement), wheezing, hypoventilation, and respiratory distress from bronchial blockage.
• The most common extracutaneous sites are the lungs and GI tract (esophagus, oropharynx, and epiglottis).

Allergic Purpura - Clinical features And Management

Allergic purpura, or anaphylactoid purpura, is a type of nonthrombocytopenic purpura. It’s characterized by allergy symptoms and acute or chronic vascular inflammation affecting the skin, joints, or GI or genitourinary (GU) tract. 

When allergic purpura primarily affects the GI tract with accompanying joint pain, it’s called Henoch-Schönlein syndrome or anaphylactoid purpura. However, the term allergic purpura applies to purpura associated with many other conditions, such as erythema nodosum. An acute attack of allergic purpura can last for several weeks and is potentially fatal (usually from renal failure); however, most patients do recover.
Fully developed allergic purpura is persistent and debilitating, possibly leading to chronic glomerulonephritis (especially following a streptococcal infection). Allergic purpura affects more males than females and is most prevalent in children ages 3 to 7. The prognosis is more favorable for children than for adults.

Causes
The most common identifiable cause of allergic purpura is probably an autoimmune reaction directed against vascular walls, triggered by a bacterial infection (particularly streptococcal infection). Typically, an upper respiratory tract infection occurs 1 to 3 weeks before the onset of symptoms. Other possible causes include allergic reactions to some drugs and vaccines, allergic reactions to insect bites, and allergic reactions to some foods (such as wheat, eggs, milk, and chocolate).

Clinical Features
Allergic purpura is characterized by purple skin lesions that are macular, ecchymotic, and varying in size, usually appearing in symmetrical patterns on the arms and legs. The lesions are caused by vascular leakage into the skin and mucous membranes and are accompanied by pruritus, paresthesia and, occasionally, angioneurotic edema. In children, the lesions are generally urticarial, and they usually expand and become hemorrhagic. Scattered petechiae may appear on the legs, buttocks, and perineum.

Malignant Melanoma

Introduction: 

Incidence of malignant melanoma, a neoplasm that arises from melanocytes, has increased by 50% in the past 20 years. In particular, an increase in incidence of melanoma in situ suggests earlier detection. The disorder varies in different populations but is about 10 times more common in white than in nonwhite populations. 

The four types of melanomas are 

1. superficial spreading melanoma, 
2. nodular malignant melanoma, 
3. lentigo maligna melanoma, and 
4. acral-lentiginous melanoma.

Melanoma spreads through the lymphatic and vascular systems and metastasizes to the regional lymph nodes, skin, liver, lungs, and central nervous system (CNS). Its course is unpredictable, however, and recurrence and metastasis may occur more than 5 years after resection of the primary lesion. If it spreads to regional lymph nodes, the patient has a 50% chance of survival.
The prognosis varies with tumor thickness. Generally, superficial lesions are curable, whereas deeper lesions tend to metastasize. The Breslow Level Method measures tumor depth from the granular level of the epidermis to the deepest melanoma cell. Melanoma lesions less than 0.76 mm deep have an excellent prognosis, whereas deeper lesions (more than 0.76 mm deep) are at risk for metastasis. The prognosis is better for a tumor on an extremity (which is drained by one lymphatic network) than for one on the head, neck, or trunk (which is drained by several networks).

Causes & Risk Factors
Several factors may influence the development of melanoma:

• Excessive exposure to ultraviolet light. Melanoma is most common in sunny, warm areas and commonly develops on parts of the body that are exposed to the sun. A person who has a blistering sunburn before age 20 has twice the risk of developing melanoma.
• Skin type. Most persons who develop melanoma have blond or red hair, fair skin, and blue eyes; are prone to sunburn; and are of Celtic or Scandinavian descent. Melanoma is rare among blacks; when it does develop, it usually arises in lightly pigmented areas (the palms, plantar surface of the feet, or mucous membranes).
• Autoimmune factors. Genetic and autoimmune effects may be causes.
• Hormonal factors. Pregnancy may increase risk and exacerbate growth.
• Family history. A person with a family history of melanoma has eight times the risk of developing the disorder.
• History of melanoma. A person who has had one melanoma has 10 times the risk of developing a second.

Clinical Manifestations
Common sites for melanoma are on the head and neck in men, on the legs in women, and on the backs of people exposed to excessive sunlight. Up to 70% arise from a preexisting nevus. They rarely appear in the conjunctiva, choroid, pharynx, mouth, vagina, or anus.

Introduction to Dermatophytosis

Introduction

Also called tinea or ringworm, dermatophytosis is a disease that can affect the scalp (tinea capitis), body (tinea corporis), nails (tinea unguium), feet (tinea pedis), groin (tinea cruris), and bearded skin (tinea barbae).
Tinea infections are quite prevalent in the United States and are usually more common in males than in females. With effective treatment, the cure rate is very high, although about 20% of persons with infected feet or nails develop chronic conditions.

Causes
Tinea infections (except for tinea versicolor) result from dermatophytes (noncandidal fungi) of the genera Trichophyton, Microsporum, and Epidermophyton that involve the stratum corneum, nails or hair.
Transmission can occur directly (through contact with infected lesions) or indirectly (through contact with contaminated articles, such as shoes, towels, or shower stalls). Some cases come from animals or soil.

Signs and symptoms
Lesions vary in appearance and duration with the type of infection:

Tinea capitis, which mainly affects children, is characterized by round erythematous patches on the scalp, causing hair loss with scaling. In some children, a hypersensitivity reaction develops, leading to boggy, inflamed, commonly pus-filled lesions (kerions).

Tinea corporis produces flat lesions on the skin at any site except the scalp, bearded skin, groin, palms, or soles. These lesions may be dry and scaly or moist and crusty; as they enlarge, their centers heal, causing the classic ring-shaped appearance.

Tinea unguium (onychomycosis) infection typically starts at the tip of one or more toenails (fingernail infection is less common) and produces gradual thickening, discoloration, and crumbling of the nail, with accumulation of subungual debris. Eventually, the nail may be destroyed completely.

Tinea pedis causes scaling and blisters between the toes. Severe infection may result in inflammation, with severe itching and pain on walking. A dry, squamous inflammation may affect the entire sole.

Skin Manifestations Of Non Malignant Systemic Diseases

The skin functions as a barrier against potentially harmful physical and chemical agents as well as against different microorganisms. Sometimes different features may be seen that help to differentiate different systemic diseases. 

A brief list of the skin manifestations of non malignant systemic diseases is given here:

1. Erythema

• Collagen disease
• Carcinoid
• Mitral valve disease
• Polycythemia
• Superior vena caval obstruction
• Liver disease
• Hyperviscosity syndrome

                                                  Facies in Primary Polycythemia vera. 

2. Erythema Multiforme

• Fever
• Inflammatory bowel disease
• Rheumatoid arthritis
• Thyrotoxicosis
• Viral Infections

                                               Erythema Multiforme (target skin lesions) 

3. Urtricaria

• Collagen disorders
• Xanthomatoses
• Hereditary angioneurotic edema
• Urtricaria pigmentosa
• Henoch-Schonlein purpura
• Cold aglutinins