What is a herald patch?
Herald patch is a skin lesion, typically marking the onset of pityriasis rosea, a skin condition. In the initial phase of this skin disease, a singular, large, round-scaled patch typically appears on the skin. These changes on the skin are referred to as herald patches. Locations that can be affected by the patch are the chest, back, neck, abdomen, and arms. Only rarely can it occur on the face, head, or penis [1, 2, 3].
In the development of pityriasis rosea, the herald patch is usually followed by the development of small erythematous papules and plaques that look like a Christmas tree on the back. On the chest, they align in a V-shape [2]. The patch often disappears on its own and is considered noncontagious compared to ringworm [3].
What causes a herald patch?
Herald patches are the primary symptom of pityriasis rosea [1]. The cause of this disease is not entirely known. However, one of the potential triggers is considered to be a viral infection [3].
How to diagnose and treat a herald patch?
The diagnosis of a herald patch is mainly based on clinical and physical findings [4]. Among the diagnostic criteria are the patch's look and the further development of the skin.
Additionally, the characteristic appearance of the herald patch fades away after approximately two weeks general rash develops [4]. Some patients can experience:
- fatigue,
- malaise,
- nausea,
- headache or joint pain,
- fever,
- enlarged lymph [4].
before or during the development of the patch,
The treatment for a herald patch focuses on symptom control. Among the medications used by the dermatologist are corticosteroids or antihistamines. Their application allows them to manage itching and inflammation. In some cases, acyclovir can be used. It is an antiviral drug that reduces the duration of the pityriasis rosea and mitigates the symptoms. In severe cases, the doctors can use UV light therapy [4].
However, the pityriasis rosea typically resolves on its own even without treatment [3].
What is a ringworm?
Ringworm is medically known as tinea. Despite its name, there are no worms involved in this condition. It is a common fungal infection that affects the top layer of the skin. The infection leads to a red circular rash on the skin. The shape often resembles a worm, which is where the name comes from [5, 6, 7].
Ringworm is highly contagious. It can be transmitted from person to person and from an animal to a person. Additionally, you can catch this fungal infection by using personal items of an affected individual, like towels, shoes, or sheets [5, 8].
Ringworm can infect any part of the body, including the hands and the head. The disease starts with a scaly, flat area. Later, the characteristic circular form appears, with a center that can be clean or filled with red bumps [6, 9].
Ringworms can have different names depending on the affected part. When a ringworm is on the foot, it is referred to as tinea pedis (athlete’s foot), and when it is on the head, it is referred to as tinea capitis [5, 7].
What causes ringworm?
Ringworm is a skin infection caused by about 40 different species of fungi. The most common are Trichophyton, Microsporum, and Epidermophyton [7]. These fungi thrive on dead tissue, like fingernails and the outer skin layer. They love especially in warm and humid conditions [10, 11].
Ringworm can be contracted in many ways. A common way is through sharing combs, towels, or clothing [7]. It can also be transmitted from animals, including dogs, cats, pigs, horses, and pigs [10].
You can catch fungi by touching infected surfaces or objects. Ringworm agents can be found on phones or floors, especially in moist environments like public showers and swimming pools [7].
Among the factors increasing the risk of ringworm are:
- hot and humid areas,
- requent sweating,
- wearing tight clothing,
- sharing clothes and towels,
- having diabetes mellitus,
- having a weakened immune system [11].
How to diagnose and treat a ringworm?
Your dermatologists can diagnose if you have ringworm. To confirm the infection, the doctor can examine the skin with a black light, for example. Some of the infective fungi are fluorescent under black light [7]. Another method that can be used is microscopy of a small skin scraping [12, 7].
Ringworm can be treated at home with antifungal medication, many of which are topical. Effective substances found in creams or gel are clotrimazole (Desenex), terbinafine (Lamisil), and miconazole (Cruex) [13]. Many of these medications are over-the-counter. Generally, the recommended length of therapy should be two to four weeks [5].
In severe cases, the dermatologist can prescribe oral antifungal drugs. Among them are itraconazole (Sporanox, Orungal) and fluconazole (Celozole) [14].