Tinea corporis; PV; Seb. Dermatitis Flashcards
Define tinea corporis / ringworm
The most common type of fungus that causes ringworm is called []. It is spread through contact with infected individuals, animals or soil.
The most common type of fungus that causes ringworm is called trichophyton. It is spread through contact with infected individuals, animals or soil.
Describe the clinical presentation of ringworm [3]
itchy rash that is erythematous, scaly and well demarcated.
There is often one or several rings or circular shaped areas that spread outwards
Tinea capitis
- can present with well demarcated hair loss. There will also be itching, dryness and erythema of the scalp. This is more common in children than adults.
Tinea pedis (athletes foot)
- presents with white or red, flaky, cracked, itchy patches between the toes.
TOM TIP: Check the toenails in someone presenting with ringworm, you may find they have a fungal nail infection that has spread to the skin.
How do you manage ringworm?
- uncomplicated [2]; complicated [2] tinea capitis [1]; nail infections [1]
Treatment of ringworm is with anti-fungal medications:
Uncomplicated cases:
- clotrimazole or terbinafine for 2 weeks or a week after the symptoms have resolved
Extensive, severe, or refractory cases:
- fluconazole, griseofulvin and itraconazole
tinea capitis:
- Anti-fungal shampoo such as ketoconazole
Nail infections:
- amorolfine nail lacquer for 6 – 12 months
Describe what is meant by tinea incognitio
Tinea incognito refers to a more extensive and less well recognised fungal skin infection that results from the use of steroids to treat an initial fungal infection.
- initial presentation of ringworm was misdiagnosed as dermatitis and a topical steroid was prescribed
- The steroid improves the itching and inflammation but accelerates the growth of the fungal infection by dampening the immune response in the local area.
- When the steroid is stopped the itchy rash caused by the fungus returns and is much worse than previously
Define pityriasis rosea
Pityriasis rosea a generalised, self limiting rash that has an unknown cause. It often occurs in adolescents and young adults. It may be caused by a virus such as human herpes virus (HHV-6 or HHV-7), but no definitive causative organism had been established.
Describe the presentation of pityriasis rosea
Systemic symptoms prior to rash developing
The rash starts with a characteristic herald patch.
- faint red or pink, scaly, oval shaped lesion that is 2cm or more in diameter
- The rash consists of widespread faint red or pink, slightly scaly, oval shaped lesions, usually less than 2 cm in diameter. On the torso they can be arranged in a characteristic “christmas tree” fashion, following the lines of the ribs.
Describe the managment of pityriasiis rosea
Usually self limiting
Topical steroids can be used for < 2 weeks to elleviate inflammation and itching
Describe what is meant by pityriasis versicolor
Common superficial fungal infection caused by the overgrowth of Malassezia species on the skin.
This yeast is part of normal skin flora but can proliferate under certain conditions such as high humidity, immunosuppression or hormonal changes
Presentation of PV?
Well-demarcated, oval or irregularly shaped macules that can range from hypopigmented to hyperpigmented.
Most patients with PV are asymptomatic although some may experience mild pruritus especially during warm humid conditions.
Describe how you would investigate PV?
Cinical features
Microscopic examination of skin scrapings treated with potassium hydroxide (KOH) can reveal the characteristic ‘spaghetti and meatballs’ appearance due to a combination of hyphae and yeast forms of the causative organism, Malassezia spp.
Treatment for PV? [2]
Topical antifungal. NICE Clinical Knowledge Summaries advise ketoconazole shampoo as this is more cost effective for large areas
If failure to respond to topical treatment then consider alternative diagnoses (e.g. send scrapings to confirm the diagnosis) + oral itraconazole
Describe the pathophysiolog of seborrhoeic dermatitis [1]
Seborrhoeic dermatitis is a chronic, recurrent inflammatory skin condition that primarily affects areas rich in sebaceous glands.
The exact pathophysiology remains unclear but Malessezia yeast species are thought to play a significant role, alongside genetic predisposition and external environmental factors.
How do you treat seborrhoeic dermatitis?
Scalp:
- first-line treatment is ketoconazole 2% shampoo
- over the counter preparations containing zinc pyrithione (‘Head & Shoulders’) and tar (‘Neutrogena T/Gel’) may be used if ketoconazole is not appropriate or acceptable to the person
Face and body management
* topical antifungals: e.g. ketoconazole
* topical steroids: best used for short periods
What is this called? [1]
What is caused by? [1]
Pyogenic granuloma
- benign vascular proliferation that commonly manifests as a rapidly growing, friable, erythematous papule or nodule, frequently observed on the skin and mucous membranes
Managament of pyogenic granuloma? [1]
Surgical excision
