Psoriasin In-shower

Dosage for Coal Tar depends heavily on the concentration of the product and the specific condition being treated. Because Coal Tar is often found in over-the-counter (OTC) products, patients should always refer to the specific 'Drug Facts' label on the packaging or follow their physician's individualized instructions.

• Psoriasis (Body): Apply a thin layer of Coal Tar ointment or cream to the affected areas 1 to 4 times daily, or as directed by a doctor. It is often most effective when applied at night and left on the skin.
• Scalp Psoriasis/Seborrheic Dermatitis: Use a Coal Tar shampoo 2 to 3 times per week. Massage the shampoo into the wet scalp and leave it in place for 5 to 10 minutes before rinsing thoroughly. Some clinicians recommend a second application immediately after the first.
• Goeckerman Regimen: This specialized clinical treatment involves applying 1% to 5% crude coal tar for several hours, followed by exposure to UVB light. This is typically performed in a hospital or specialized clinic setting.

Coal Tar is generally not recommended for use in children under the age of 2 unless specifically directed by a pediatrician. For children older than 2, the dosage is typically the same as the adult dose, but extra care should be taken to monitor for skin irritation or systemic absorption due to the higher surface-area-to-weight ratio in pediatric patients. Always consult a healthcare provider before using Coal Tar products on children.

Renal Impairment

There are no specific dosage adjustments provided by manufacturers for patients with kidney disease, as systemic absorption is low. However, if Coal Tar is applied to very large areas of the body for prolonged periods, patients with severe renal impairment should be monitored, as the kidneys are responsible for excreting any absorbed metabolites.

Hepatic Impairment

Similar to renal impairment, specific adjustments are not standard for topical use. However, because the liver metabolizes polycyclic aromatic hydrocarbons (PAHs), patients with advanced liver disease should use Coal Tar under close medical supervision if applying to extensive areas of the skin.

Elderly Patients

Older adults often have thinner, more fragile skin. While no specific dosage reduction is required, elderly patients should be monitored for increased skin irritation or sensitivity. Healthcare providers may recommend starting with lower concentrations (e.g., 0.5% or 1%).

1. 1Preparation: Wash your hands before and after application. Clean the affected skin area with mild soap and water and pat dry before applying the medication.
2. 2Application: Apply a small amount and rub in gently. If using a shampoo, ensure the scalp is thoroughly wet. Do not apply to skin that is infected, blistered, or oozing unless directed by a doctor.
3. 3Avoid Sensitive Areas: Keep Coal Tar away from the eyes, nostrils, mouth, and genital area. If contact occurs, rinse with cool water for 15 minutes.
4. 4Sun Protection: Coal Tar increases your sensitivity to sunlight. Avoid sunlamps and tanning beds. If you must be outdoors, wear protective clothing and apply sunscreen to untreated areas.
5. 5Storage: Store Coal Tar products at room temperature (59°F to 86°F or 15°C to 30°C). Keep the container tightly closed and away from heat sources, as some formulations (especially gels) may be flammable.

If you miss a dose, apply it as soon as you remember. If it is almost time for your next scheduled application, skip the missed dose and return to your regular routine. Do not apply double the amount of Coal Tar to make up for a missed dose, as this increases the risk of skin irritation.

Topical overdose is unlikely to cause life-threatening symptoms but may result in severe skin irritation, redness, or chemical burns. If the product is accidentally swallowed, contact a Poison Control Center (1-800-222-1222 in the US) or seek emergency medical attention immediately. Symptoms of ingestion may include nausea, vomiting, and irritation of the digestive tract.

> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose or frequency of use without medical guidance.

Coal Tar is generally well-tolerated, but its chemical nature can lead to several common reactions. Most of these are localized to the site of application:

• Skin Irritation: Many patients experience mild stinging, burning, or redness upon application. This usually subsides as the skin adjusts to the medication.
• Photosensitivity: Coal Tar significantly increases the skin's sensitivity to ultraviolet (UV) light. This can lead to a 'tar burn' (a severe sunburn-like reaction) even with brief sun exposure. This sensitivity can persist for up to 72 hours after the last application.
• Staining: Coal Tar is notorious for staining. It can temporarily discolor skin and fingernails and permanently stain light-colored hair (especially blonde, grey, or bleached hair). It also stains clothing, bedsheets, and towels.
• Unpleasant Odor: The strong, 'medicinal' or 'asphalt-like' smell of coal tar is a frequent complaint and can linger on the skin and hair for hours.

• Folliculitis: This is an inflammation of the hair follicles. It appears as small, red, itchy bumps or pimples at the site of application. It is most common when coal tar is used on hair-bearing areas like the legs or arms and then covered with tight clothing or bandages.
• Contact Dermatitis: Some individuals may develop an allergic-like reaction characterized by itching, swelling, and small blisters (vesicles).
• Dry Skin: While used for scaly conditions, the alcohol base in some coal tar gels or shampoos can cause localized dryness or cracking of the skin.

• Severe Allergic Reactions: Though rare for a topical product, systemic hypersensitivity can occur. Symptoms include hives, difficulty breathing, and swelling of the face or throat.
• Atrophy: Prolonged, excessive use under occlusion might lead to slight thinning of the skin, though this is much less common than with topical steroids.

> Warning: Stop using Coal Tar and call your doctor immediately if you experience any of these serious reactions:

• Severe Sunburn: If you experience intense blistering, swelling, or pain after sun exposure while using coal tar.
• Widespread Skin Rash: A rash that spreads beyond the area of treatment or is accompanied by a fever.
• Signs of Infection: Increased swelling, warmth, pus, or red streaks extending from the treated area.
• Anaphylaxis: Sudden dizziness, rapid heartbeat, or swelling of the tongue/throat (this is a medical emergency).

One of the most discussed long-term concerns regarding Coal Tar is its potential carcinogenicity (cancer-causing potential). Coal Tar contains polycyclic aromatic hydrocarbons (PAHs), which are known carcinogens in industrial settings (such as for chimney sweeps or coke oven workers). However, epidemiological studies of patients using therapeutic Coal Tar for decades have generally failed to show a significantly increased risk of skin cancer or internal cancers. A landmark study published in the Journal of Investigative Dermatology (2010) followed over 13,000 patients and found no increased risk of cancer associated with coal tar use. Despite this, the FDA requires a warning on products, and California’s Proposition 65 lists coal tar as a known carcinogen.

Another long-term effect is 'tar acne,' a condition similar to folliculitis where chronic exposure to tar leads to the formation of comedones (blackheads) and inflammatory papules on the skin.

No FDA black box warnings currently exist for Coal Tar. It is considered safe for its intended over-the-counter and prescription uses when label directions are followed. However, it is subject to specific labeling requirements regarding sun exposure and use on broken skin.

Report any unusual symptoms or persistent irritation to your healthcare provider to ensure the treatment remains safe for you.

Coal Tar is a potent pharmacological agent and must be used with caution. It is intended for external use only. Patients should be aware that Coal Tar can be messy and has a distinct odor that may affect treatment compliance. It is vital to avoid applying Coal Tar to the face, groin, or axilla (underarms) unless specifically instructed by a dermatologist, as the skin in these areas is thinner and more prone to irritation and increased absorption.

There are no FDA black box warnings for Coal Tar. It has been used clinically for over a century with a well-established safety profile for topical administration.

• Photosensitivity Warning: This is the most critical precaution. Coal Tar makes your skin significantly more prone to severe sunburn. This effect is not limited to the time the tar is on your skin; the sensitivity can last for several days after the product is washed off. Patients must avoid sunlamps and limit sun exposure for at least 72 hours after use.
• Skin Inflammation: Coal Tar should not be applied to skin that is acutely inflamed, weeping, or blistered (e.g., during an acute flare of erythrodermic psoriasis). Applying tar to such areas can worsen the inflammation and increase the risk of systemic absorption.
• Allergic Sensitivity: While rare, some individuals are hypersensitive to coal tar or its components. A 'patch test' (applying a small amount to a tiny area of skin for 24 hours) is often recommended before starting widespread treatment.
• Staining and Discoloration: Coal Tar will stain almost anything it touches. It can turn blonde, bleached, or grey hair a yellowish or brownish color. It can also stain skin and nails temporarily. Patients should use old towels and bedsheets during treatment.

For standard over-the-counter use, intensive laboratory monitoring is generally not required. However, for patients undergoing intensive therapy (like the Goeckerman regimen) or applying tar to more than 25% of their body surface area, healthcare providers may occasionally monitor:

• Skin Exams: Regular checks by a dermatologist to monitor for folliculitis or any suspicious skin lesions.
• Urinalysis: In rare cases of extreme exposure, clinicians might check for the presence of coal tar metabolites, though this is not standard practice for most patients.

Coal Tar is a topical medication and does not typically enter the bloodstream in amounts large enough to cause sedation or cognitive impairment. It is considered safe to drive or operate machinery while using this medication.

There are no known direct interactions between topical Coal Tar and moderate alcohol consumption. However, alcohol can be a trigger for psoriasis flares in some individuals, so patients are encouraged to discuss their alcohol intake with their doctor.

Coal Tar does not cause physical dependence or a withdrawal syndrome. However, stopping treatment abruptly may lead to a recurrence of psoriasis or seborrheic dermatitis symptoms. It is often best to gradually reduce the frequency of application (e.g., from daily to twice weekly) once the skin has cleared, a process known as maintenance therapy.

> Important: Discuss all your medical conditions, including any history of skin cancer or sun sensitivity, with your healthcare provider before starting Coal Tar.

There are no absolute drug-drug contraindications where Coal Tar must never be used with another medication. However, certain combinations are avoided to prevent severe skin damage:

• Methoxsalen (Psoralen): When used in PUVA therapy (Psoralen + UVA), adding Coal Tar without strict medical supervision can lead to extreme photosensitivity and severe, deep-tissue burns. This combination is only used in highly controlled clinical settings.

• Other Photosensitizing Medications: Drugs that already increase sun sensitivity can have an additive effect with Coal Tar. These include:
• Tetracyclines (e.g., Doxycycline)
• Fluoroquinolones (e.g., Ciprofloxacin)
• Sulfonamides (Sulfa drugs)
• Thiazide Diuretics (e.g., Hydrochlorothiazide)
• Phenothiazines (e.g., Promethazine)
• NSAIDs (e.g., Naproxen, Piroxicam)

Clinical Consequence: Using these together significantly increases the risk of severe phototoxic reactions (sunburns).

• Topical Corticosteroids: Coal Tar is often used in rotation or combination with topical steroids (e.g., Clobetasol, Hydrocortisone). While this is a common therapeutic strategy, using them simultaneously on the same patch of skin can sometimes increase the risk of folliculitis or skin thinning. Usually, doctors recommend applying the steroid in the morning and the tar at night.
• Topical Retinoids: Medications like Tazarotene or Tretinoin also thin the stratum corneum and increase irritation. Combining these with Coal Tar may lead to excessive skin peeling and discomfort.

There are no documented interactions between topical Coal Tar and specific foods, including grapefruit, dairy, or caffeine. Because the medication is applied to the skin, its absorption is not affected by the contents of the stomach.

• St. John's Wort: This herbal supplement is known to cause photosensitivity. Patients taking oral St. John's Wort should be extra cautious when using Coal Tar due to the cumulative risk of sun-related skin damage.
• Vitamin A Supplements: High doses of Vitamin A can increase skin sensitivity and dryness, potentially worsening the localized side effects of Coal Tar.

Coal Tar is not known to interfere with standard blood chemistry, hematology, or coagulation tests. However, it may affect:

• Urinary 1-hydroxypyrene: If you are being screened for industrial chemical exposure, the use of therapeutic coal tar will cause a false-positive elevation in this biomarker.

Mechanism of Interactions: Most interactions with Coal Tar are pharmacodynamic, meaning the drugs have additive effects on the same organ (the skin) or the same physiological process (photosensitivity). There is little evidence of pharmacokinetic interactions (where one drug changes the blood levels of another) because coal tar's systemic presence is so low.

> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, especially those that make you sensitive to the sun.

Coal Tar must NEVER be used in the following circumstances:

1. 1Known Hypersensitivity: If you have had a previous allergic reaction to coal tar, wood tar, or any component of the formulation (such as parabens or fragrance in the base), you must not use this product. Anaphylaxis or severe contact dermatitis could occur.
2. 2Active Skin Infection: Coal Tar should not be applied to skin that is currently infected with bacteria (e.g., impetigo), viruses (e.g., herpes simplex), or fungi. The occlusive nature of some tar preparations can trap pathogens and worsen the infection.
3. 3Acutely Inflamed or Weeping Skin: In conditions like 'wet' eczema or erythrodermic psoriasis where the skin is raw and oozing, Coal Tar is too irritating and can lead to severe pain and systemic absorption through the compromised skin barrier.

Conditions requiring a careful risk-benefit analysis by a physician:

• History of Skin Cancer: Because Coal Tar contains PAHs, patients with a personal or strong family history of squamous cell carcinoma or basal cell carcinoma should use it with caution and under regular dermatological surveillance.
• Photosensitivity Disorders: Patients with conditions like Lupus Erythematosus or Xeroderma Pigmentosum, which already cause extreme sun sensitivity, should generally avoid Coal Tar.
• Pustular Psoriasis: While tar is good for plaque psoriasis, it can sometimes irritate pustular forms of the disease, potentially causing a flare.
• Children under 2 years: The safety and efficacy in infants have not been established, and the risk of systemic absorption is higher.

Patients who are allergic to Pine Tar, Juniper Tar, or Birch Tar may also react to Coal Tar. Additionally, individuals sensitive to Balsam of Peru or certain fragrances may have a higher likelihood of reacting to the complex chemical mixture found in Coal Tar products.

> Important: Your healthcare provider will evaluate your complete medical history, including any previous reactions to topical products, before prescribing or recommending Coal Tar.

FDA Pregnancy Category: Coal Tar is generally classified as Category C. This means that animal reproduction studies have shown an adverse effect on the fetus (when coal tar was ingested or applied in very high doses), but there are no adequate and well-controlled studies in humans.

• Risks: Some components of coal tar, such as polycyclic aromatic hydrocarbons, can cross the placenta. While topical use involves minimal absorption, the risk is not zero.
• Clinical Guidance: Most dermatologists recommend avoiding coal tar during the first trimester. If used later in pregnancy, it should be applied to the smallest area possible for the shortest duration. Many providers prefer using topical steroids or light therapy as safer alternatives during pregnancy.

It is not known whether the components of Coal Tar pass into human breast milk in significant quantities. However, the primary risk is direct contact.

• Precautions: Coal Tar should never be applied to the breasts or nipples of a nursing mother to prevent the infant from accidentally ingesting the medication or coming into contact with it.
• Recommendation: If Coal Tar must be used on other parts of the body, the mother should wash her hands thoroughly before handling the baby.

Coal Tar is FDA-approved for use in children over 2 years of age for the treatment of psoriasis and seborrheic dermatitis.

• Dosing: Use the lowest effective concentration.
• Monitoring: Children have a higher surface-area-to-volume ratio, meaning they can absorb more medication through their skin than adults. Monitor closely for signs of irritation or folliculitis.
• Restrictions: Do not use in infants under 2 years old without direct medical supervision.

Older patients may benefit from Coal Tar, but several age-related factors must be considered:

• Skin Fragility: Elderly skin is often thinner (atrophic), which may increase the risk of irritation and absorption.
• Polypharmacy: Older adults are more likely to be taking systemic medications that cause photosensitivity (like diuretics or heart medications), increasing the risk of 'tar burns.'
• Application: Physical limitations (arthritis) may make it difficult for elderly patients to apply tar to hard-to-reach areas like the back.

While topical Coal Tar is not known to be nephrotoxic (toxic to kidneys), its metabolites are excreted renally. In patients with end-stage renal disease (ESRD), there is a theoretical risk of metabolite accumulation if the drug is applied to very large surface areas. Use with caution in patients with a GFR < 30 mL/min.

Since the liver is responsible for processing polycyclic aromatic hydrocarbons, patients with severe hepatic impairment (Child-Pugh Class C) should be monitored if using Coal Tar extensively. However, for standard scalp or localized plaque treatment, no dosage adjustment is typically necessary.

> Important: Special populations require individualized medical assessment to weigh the benefits of Coal Tar against potential risks to the fetus, infant, or patient.

Coal Tar's pharmacology is multi-faceted. At the molecular level, it acts as a ligand for the Aryl Hydrocarbon Receptor (AhR). Once activated, the AhR moves into the cell nucleus and regulates the transcription of genes that control keratinocyte (skin cell) growth and differentiation. This leads to an increase in the production of skin barrier proteins and a decrease in the rapid, 'immature' cell growth seen in psoriasis.

Furthermore, Coal Tar has antimitotic effects. It appears to interfere with the synthesis of DNA in the basal layer of the epidermis, which reduces the rate of skin cell turnover. In psoriasis, cells move from the bottom layer to the surface in 3-4 days (instead of the normal 28 days); Coal Tar helps normalize this transit time. It also inhibits the enzyme thioredoxin reductase, which is overexpressed in psoriatic skin.

• Onset of Effect: Improvements in itching (pruritus) may be felt within a few days. However, the thinning of thick psoriatic plaques usually takes 2 to 4 weeks of consistent use.
• Duration of Effect: The benefits of a Coal Tar course can last for several weeks to months after discontinuation, a period known as 'remission.'
• Tolerance: Unlike topical corticosteroids, Coal Tar does not typically exhibit tachyphylaxis (a rapid decrease in response to a drug after repeated doses).

| Parameter | Value |

|---|---|

| Bioavailability | Low (Topical); <5% systemic absorption |

| Protein Binding | N/A (Localized effect) |

| Half-life | Variable (Metabolites ~6-12 hours) |

| Tmax | 4-8 hours (for skin penetration) |

| Metabolism | Hepatic (CYP1A1, CYP1A2) for absorbed components |

| Excretion | Renal (Primary route for metabolites) |

• Composition: A complex mixture of over 10,000 compounds, including benzene, toluene, xylenes, phenols, and naphthalene.
• Solubility: Insoluble in water; partially soluble in alcohol, ether, and chloroform.
• Physical State: A nearly black, viscous liquid with a characteristic naphthalene-like odor.

Coal Tar is classified as an Antipsoriatic and a Keratolytic. It is grouped with other topical treatments like Salicylic Acid (often used in combination with tar) and Anthralin. It is distinct from the 'biologic' class of psoriasis drugs which are injected and target specific immune pathways.